Mayuri's appearance has a skeletal look to it with a skull-like visage. His face is painted entirely white with the inner portion of his face painted black with the exception of his nose. His eyes are a golden color and he constantly bares his teeth giving the appearance of him constantly smiling. Both his ears are seemingly replaced with stubbed golden cones. His fingernails are blue and, with the exception of the fingernail on his right middle finger, are all short. The one long fingernail is as long as the finger itself. He also wears a white hat with two ends that point to his right and a large purple scarf around his neck. His whole body, even his face and hands, has been painted black and white. He repaints his make-up every morning, as he always removes it before going to bed.
Without his makeup, Mayuri has blue hair and honey gold eyes. He has small, slatted portcullises with multiple earrings in place of where his ears would be, and his body is covered in scars.
Upon entering Hueco Mundo, Mayuri reveals a new look: his face paint had changed with him creating a black cross upon the center of his face covering everything but his nose and a small portion of his lower chin. His ear attachments have become shorter and rounder but wider, his chin has a long golden attachment reminiscent of an Egyptian Pharaoh beard, his teeth have become a golden color, and he no longer wears a hat as there is a golden frame around his face. His hair is also styled into "horns," that slope down from the top of his head and frame his face, which when viewed from the front looks much like a Pharaoh's crown.
17 months after Aizen's defeat, Mayuri displays another new look. The black face paint covers much of his face, leaving thin white lines going up his face and a white nose. He wears a long, golden headdress which curves back to his mid back. Underneath his chin are two opposite facing strands from the mask. On the backside of the headdress the Twelfth Division symbol is painted.
Following the first invasion by the Wandenreich, Mayuri dons a bright white overcoat with many ridges on the front. The overcoat also has a hood that has many protrusions that give the appearance of a sun. The shoes he wears have changed to be a plain white pair with the shoes splitting into opposite points at the toe.
Under this outfit he has styled his hair into three loops, and his ears are covered by three large golden tubes that wrap around the sides of his head. 
10 years after Yhwach's defeat, Mayuri's face is painted to resemble a white-and-black mask, with the white portion circling his forehead and covering his upper lip and nose, while the black portions consist of his lower lip, chin, and most of his forehead as well as the area around his eyes. He now wears a large golden headpiece resembling a pair of ram's horns curling backward behind his head.
110 years ago, Mayuri's appearance was similar to his current appearances, but with minimal details. He was still largely painted white except for the black paint which was arranged around his eyes like a large domino mask. He had gold cones covering his ears and blue hair combed back on the top of his head.
While developing the Nemuri Project, Mayuri's makeup consisted of black, geometrical shapes covering the area of his face above his nose and mouth, with thick lines extending to his jaw, and he retained the gold cones on his ears while donning an oddly-shaped hat.
Mayuri Kurotsuchi is a researcher and personifies the stereotype of the mad scientist. By his early actions during the Ryoka Invasion, he is displayed as sadistic and cruel. He sees everyone and everything not as a living being, but as an object to be researched—including himself. He has little respect or regard for most others, and was even willing to turn his own men (who were not aware of his plans) into living bombs in an attempt to capture Uryū Ishida and Orihime Inoue for experimentation. He also withheld vital information about the Bounts from the other Shinigami in order to capture one as a research subject for himself. However, while he usually shows disregard for life, he has been known to warn people of possible dangers when they present themselves. As a scientist, Mayuri despises perfection, as he believes that achieving such a state leaves him with absolutely nothing more to strive for — namely imagination, knowledge and improvements — which would result in nothing but despair; because of this, he derided Szayelaporro Granz for claiming to be a "perfect life form".
It is known that Mayuri's favorite food is pike fish, and that he does not like onion. One of his free-time activities is reading every character published in Seireitei Communication. He himself publishes a serialization in the journal, titled "Effective Medication for the Brain", which apparently contains detailed instructions on preparation of medicine and their application. Surprisingly, it is highly popular among the readers.
In battle, Mayuri likes to toy with his opponent, torturing them little by little until they can hardly stand. He did this in both the fight with Uryū and his Espada counterpart Szayelaporro. Every time he fights he uses it as an experiment testing himself and his opponent little by little. He also uses it as an opportunity to implant microbes or other things in case they get away. Before engaging, though, he will make extensive research on his possible opponents to tilt the chance of winning in his favor. Before the Winter War, he is busy reading in the library with a note on the door saying, "Enter and Die."
Mayuri's utter disregard for life even extends to the rest of the Gotei 13, believing that all members of the organization are to be prepared to give up their lives in order to protect the Seireitei. To this end, he would gladly cut down any former comrades, even if they are under the enemy's control, test many of his experimental drugs on such comrades for the sake of his research which he believes to be the sake of the Seireitei, and even force his zombified fellow captains to become his minions to fight to their last breath for the sake of Gotei 13 and Soul Society, as opposed to killing them out of mercy.
Despite his disregard for most life, Mayuri is very obsessive about creating it, and it is his dream to create a soul out of nothing. This led to him being overjoyed when the seventh test of the Nemuri Project was successful.
Little is known about the early history of Mayuri, except that 110 years ago, he was the only prisoner in the Maggot's Nest who was considered dangerous enough to necessitate confinement in a small prison cell, chained to the wall by his ankle. He would, however, one day be visited by Kisuke Urahara who was seeking his genius to become vice-president in the newly thought-of Shinigami Research and Development Institute, a request that would automatically get him out of there. At first Mayuri refused, until Kisuke began teasing him with the fact that he had nothing to tinker with down there and that, as vice-president, he would inherit everything should something happen to Urahara.
At some point, Mayuri read a book detailing the functions of the arms of the Soul King, where he learned that the right arm is in charge of "stopping" while the left arm is in charge of "advancing".
9 years later, while walking through the Seireitei with Kisuke Urahara and Hiyori Sarugaki, they were greeted by 5th Division Captain Shinji Hirako and his Lieutenant Sōsuke Aizen. Mayuri expressed distaste for Shinji as he refused to call Mayuri by his full name and only called him by his first, which was too familiar for Mayuri's liking. He acted uninterested in the conversation between Urahara and Aizen who was explaining that the 9th Division had been sent on a special investigation to find out what was happening with the disappearances in the Rukongai.
During her brief time as a member of the institute, Hiyori served as a lab manager, which resulted in clashes with Mayuri, who was then 3rd Seat & Vice-President of the Shinigami Research and Development Institute, over who had more authority under the captain. The two constantly got into an ongoing argument about who was in charge, prompting Hiyori to call in Urahara. He explained to her that with the disappearances occurring he had created a new type of Gigai. Before Hiyori could respond they were interrupted by the arrival of Tōdō Izaemon, the 6th Seat of the 9th Division. Urahara agreed to send a researcher over to the investigation site as per the request of Captain Kensei Muguruma of the 9th Division. Urahara elected Hiyori to go to the site, to which she became irritated and asked why he couldn't send someone less important, referring to lab assistant Akon. He questioned if she should continue being a lieutenant prompting Hiyori to attack him, though he simply dodged her. Though reluctant, Hiyori gave in once Urahara explained that she was the only one that he could trust with the task.
At some point, Mayuri began developing the Nemuri Project, which he used to modify his Zanpakutō. This development allowed him to succeed Urahara as captain of the 12th Division of the Gotei 13. In the project, he eventually created new life from "godly soul cells" in the form of Nemu, which made him extremely happy. Though he claimed that creating new souls from nothing was the dream of any Shinigami, Mayuri believed that having a dream while awake was foolish and reflected that in the ironic name of the project.
Years later, after the issue of Shinigami being killed in Naruki City was solved, Mayuri listened to Isshin Shiba's report about his findings in a captains' meeting. Although the Captain-Commander was willing to overlook Isshin's violation of rules, Mayuri expressed his displeasure at how Isshin couldn't bring back the body of the "Mysterious Hollow".
He also experimented on Quincy, including Sōken Ishida, Uryū's master and grandfather, in his studies. He was disappointed to learn that Uryū was a Quincy because he considered his study of the Quincy complete and did not want any further Quincy specimens.
Soul Society arc
Mayuri is present at a meeting of the Gotei 13 captains which is convened so that Captain Gin Ichimaru can explain his suspicious actions. Gin, being one of the thirteen captains, should have had no trouble destroying Ichigo and his friends. Gin merely chalks it up to a mistake on his part. Though Mayuri and Kenpachi Zaraki argue over the possibility of him purposefully letting them go, which grows into an argument between the two until they are silenced by Captain-Commander Yamamoto.
During the Ryoka Invasion of Soul Society, Mayuri attempts to search for the Ryoka and use them as test subjects. During the search, Mayuri tries to give an unsanctioned interrogation to Ikkaku Madarame while he is healing in the 4th Division headquarters. Ikkaku refuses to tell him the details of his fight. Disturbed that Ikkaku has nothing to offer, he states that he will need to be punished for his behavior, though Mayuri is promptly stopped by Zaraki (who asks him since when does he have authority over the members of other divisions). Mayuri quickly leaves.
He eventually meets up with Uryū Ishida and Orihime Inoue, whom he tries to capture using his own squad members as bombs. After Mayuri blows up the last of his men, he sees Orihime's Santen Kesshun technique has protected her and Uryū from the blast. Uryū turns his sights on Mayuri, who is now interested in studying Orihime because of her shield, asking if she would like to be his research subject. Mayuri, undeterred by Uryū, continues to add incentives to Orihime to become his subject by issuing offers he normally wouldn't. Mayuri then notices Uryū standing next to him pointing a bow, and tells him that he is pretty fast for a Quincy. Mayuri then states that they are a rare breed and he hasn't seen one alive for many years, but he notes that he has no interest in the Quincy as he finished studying their kind some time ago. When this causes Uryū to question who he is, Mayuri is taken aback at the idea that Uryū and his friends would invade Soul Society without doing their homework; at the very least they should know who the Gotei 13 captains were. Mayuri then gives his name, rank and position. Now realizing what they are up against, Uryū tells Orihime to run for it as he takes on Mayuri. Not about to lose a test subject, Mayuri extends his arm to catch Orihime, but it is shot off by one of Uryū's spiritual arrows.
Mayuri is disappointed at the state of his extension arm and detaches it from his body much to Uryū's surprise. He then takes out and uses his Hojiku-Zai which instantly regenerates his arm further surprising Uryū. He remarks that it really doesn't matter if Orihime got away, as he can always track her down, and the sooner he does the sooner he can begin testing. Uryū fires his spiritual arrows at him, but Mayuri dodges the first couple of shots and then uses Shunpo to maneuver to a nearby roof. Mayuri makes note that Uryū has been using Hirenkyaku, an advanced Quincy technique similar to Shunpo. Though Mayuri can use Shunpo to counter the technique, it is tiresome to use and he comments that he can't have Uryū moving all over the place; he resolves to kill him. Mayuri then releases his Shikai and before Uryū can counter with a spirit arrow he is blocked by Mayuri's lieutenant, Nemu, causing them both to be injured by Mayuri's attack. Mayuri is livid that Nemu had let go of Uryū after the attack, and hits her as she begs for forgiveness. Mayuri then turns his attention back to Uryū to finish him off.
When Nemu begins to beg for medical help, he becomes enraged and goes over to her and begins to stomp on her for her insolence. When Uryū protests at Mayuri's treatment of his own subordinate, Mayuri claims that she won't die from her injuries as he created her body himself and tells Uryū that she is a construct entirely of his making and therefore his "daughter". He then tells Uryū not to dare try and tell him how to treat her, but Uryū still screams out in protest only to realize that his arm is paralyzed. Mayuri proceeds to tell him what the special ability of his Zanpakutō is, and then stabs Uryū in his arm once again causing him to scream out in pain. Mayuri then tells Nemu to kill him, but then realizes that she is paralyzed because of the attack as well and stomps on her again. Before he stabs her again with his Zanpakutō, Uryū screams that he should stop, prompting Mayuri to question whether his philosophy has to do with the Quincy pride that his people were always talking about before they died. Uryū asks what he is talking about and Mayuri details how once he studied the Quincy (though his studies seemingly only included every horrible and cruel treatment possible, more akin to torture) and had ended his study years ago. He sneers that before dying they would always swear on the pride of the Quincy. Uryū listens on in absolute shock as he hears of the butchering of his people. Mayuri then offhandedly reveals that he was the one who orchestrated the death of Uryū's grandfather, Sōken Ishida, and even shows Uryū a photograph of him.
Uryū is enraged by the truth of his grandfather's death and swears on the pride of the Quincy to kill Mayuri. He then uses an advanced and rare Quincy technique called Ransōtengai, to control his paralyzed body like a puppet. Mayuri notes that he had never actually seen the technique in any of the 2661 Quincy he studied and is surprised that someone so young can use it. Mayuri then takes out his hidden Kusarigama and resolves that since he is starting to find Uryū interesting, he will keep him alive to study as well. But much to Mayuri's surprise, Uryū removes his Sanrei Glove to gain the power to defeat the captain.
Mayuri is utterly surprised as he has never seen this technique before and is unsure of what even happened. He then notices that Uryū is absorbing the surrounding structures, then deduces that since everything in Soul Society is made of Reishi, he is absorbing them and turning them into strength. Mayuri tells Uryū that he has gone far beyond the limits of Humans, but Uryū's only response is the creation of a complex bow construct, from which he fires a spiritual arrow, which Mayuri dodges. To his surprise, Uryū appears above him and shoots him, causing a large explosion. Uryū offers to spare Mayuri if he begs for mercy and never appears in front of him again. He threatens to shoot him with a spiritual arrow three times stronger than the last shot if he does not. The previous arrow grievously injured Mayuri, having destroyed his left arm. Now enraged, he chastises Uryū for his arrogance and declares that he could match his power, and laughs. After doing so, he releases his Bankai. Mayuri explains that the poison his Bankai releases would surely kill him, though Uryū states that his arrow will reach Mayuri long before his Bankai's fatal poison can be released. Mayuri sends his creature charging at Uryū, who fires his arrow, splitting it in half and shooting a hole through Mayuri's abdomen.
Despite the fatal injuries, Mayuri still lives and much to Uryū's surprise, stabs himself in the throat with his Zanpakutō, allowing him to use its ability to turn himself into liquid so that he could escape, seeping into the cracks of the area. Later, he hears of Isane Kotetsu's announcement of Aizen's treachery after reforming, but upon being asked by Nemu he refuses to get involved, saying that he is not interested.
Bount arc (anime only)
Note: Events occurring in this arc are only in the anime and do not constitute canon material.
Click "show" to read the arc plot.
Mayuri appears again during the Bount Invasion of Karakura Town, he is in his office when he is approached by 8th Division Captain Shunsui Kyōraku in reference to having any information on the Bounts. Mayuri flat out refuses to share any information with the inquisitive captain. Not long after Kyōraku leaves, Mayuri finds that all his files on the subject have been erased. Mayuri later calls a meeting of the captains and informs them that there is a traitor among them whom has erased the information from his database, not realizing it was former 11th Division member Maki Ichinose.
Mayuri explains to the captains the history of the Bounts. Telling a story about a war between the Quincy and the Bounts, which ended in a Bount defeat. The biggest incident to come out of this defeat is the Bounts consuming living souls to increase their power. Mayuri then deduces that the number of people will increase as the Bounts become more active.
Mayuri finds the information on the Bounts and wanting a Bount test subject, he sends Nemu to give Uryū an artifact that will temporarily restore his Quincy powers in exchange for helping the Bount to reach Soul Society (which he assumes will occur). Meanwhile General Yamamoto begins suspect Mayuri of treason and send Byakuya to search in his families archives for information on the Bounts.
When the Bounts attack Soul Society, Mayuri decides to prove his loyalty by defeating one of the Bount, Sawatari. Sawatari attacks Mayuri with his doll, Baura, and manages to rip Mayuri's left arm off. Mayuri regenerates his arm with his medicine, and uses his Zanpakutō to paralyze Sawatari's doll, Baura. Mayuri then stabs Sawatari in the right arm. Baura then manages to overcome the paralysis to retreat with Sawatari into another dimension. Sawatari surfaces in another location in Seireitei, and Mayuri appears, revealing that he made a scanner to track the Bount. Sawatari attacks Mayuri with the power of other Shinigami that Baura absorbed in previous battles. Mayuri is forced to use his Bankai, and kills Sawatari. The confrontation leaves him severely injured afterwards, largely due to his persistence in trying to capture the Bount alive at first.
When Yamamoto calls the Gotei 13 captains for an emergency meeting, Mayuri is among those that attend.
The New Captain Shūsuke Amagai arc (anime only)
Note: Events occurring in this arc are only in the anime and do not constitute canon material.
Szayelaporro attempts to use his Resurrección's voodoo ability and, at first, seemed to have easily beaten Mayuri. Suddenly, Mayuri stands up and taunts Szayelaporro which causes the Espada to continue to destroy organs, but this time it has no effect. As it turns out, Mayuri had taken precautions against this ability by implanting himself with fake organs, having studied the technique beforehand using data from bacteria he implanted within Uryū during their last battle (much to Uryū's annoyance). Szayelaporro then takes Nemu captive, but Mayuri releases his Bankai and devours Szayelaporro with it. Szayelaporro uses the rebirth power of his Resurrección to recreate himself inside Nemu, but in doing so is affected by chemicals contained inside Nemu's body. Mayuri is highly intrigued by this new power, and requests to see what other powers his opponent has. To give him what he asked for, Szayelaporro uses his possession ability to control Mayuri's Bankai, but Mayuri already had countermeasures set in place for just that possibility; his Bankai self-destructs, reverting to its sealed state.
Mayuri, disappointed at Szayelaporro's lack of any further abilities, explains that by recreating himself inside Nemu, Szayelaporro is now dosed with one of many special drugs placed inside her body. The one he just absorbed is a sense-enhancing chemical that he instantly names a 'superhuman drug', as it were. The drug increases Szayelaporro's senses to the point that his body falls grossly behind and cannot move, paralyzing him as seconds become centuries. Mayuri then berates Szayelaporro for his statement as a scientist that he was the perfect being. He then proceeds to pierce Szayelaporro's hand and continues to slowly thrust his Zanpakutō through to Szayelaporro's heart, wishing him a pleasant eternity, before breaking off the blade as the ultimate torture for Szayelaporro and also as punishment for his Zanpakutō striking at its master.
After searching for Szayelaporro's laboratory throughout the rubble, he realizes that he cannot ask Nemu for help. Musing that she is such a "pain in the ass", he revives Nemu with rather odd and possibly very explicit means and has her dig out Szayelaporro's laboratory, within which are a pair of bodies suspended from the ceiling. After this he continues to heal Uryū and Renji, the latter being healed first so he could go and help in the other concurrent fights. Once he is finished healing Uryū, he gives him an anti-Arrancar mine that he invented.
Fake Karakura Town arc
When Byakuya Kuchiki tells Ichigo Kurosaki to go back to Karakura Town, Ichigo complains that he could not get back that easily on his own, and that Kisuke Urahara was not there to open the Garganta. Mayuri then suddenly appears behind the group with Nemu pushing a loaded wagon behind him and complains about the fact that Ichigo is constantly fixated on Urahara. He then notes how Ichigo used no honorifics to address him, but muses about the fact that he was better than Byakuya and Kenpachi, whom Ichigo would only address using their given names.
Byakuya takes notice of his unusually lenient mood and asks if it has something to do with the wagon behind him. Mayuri confirms this and tells him that he is in a good mood because, not only has he found some "spoils of war", but at the same place he was also able to analyze the structure of the Garganta. When Ichigo questions his statement, Mayuri begins to rant about what he had learned and orders Nemu to make preparations to send the substitute Shinigami to the Human world. When Ichigo further complains, Mayuri explains to Ichigo that this process was an experiment, and that Ichigo is "Test Subject Number 1" and therefore, he has no right to refuse or to accept.
Retsu Unohana then arrives and says she'll accompany Ichigo back. Mayuri is surprised that she'd offer to be a test subject too, but she smiles and says that she has faith in him and that she believes the experiment will be a success. Besides that, if Mayuri failed to make a Garganta, even after analyzing information found in Hueco Mundo, then Urahara would laugh at him. Mayuri reminds her that he could close the Garganta during the transfer, which she merely acknowledges as being true. Unohana only says that she expects no less. He then opens the Garganta to let both Ichigo and Unohana through. Before Ichigo leaves with Unohana, Ichigo tells Mayuri how he is similar to Kisuke, which infuriates him. After Ichigo leaves, Mayuri comments to himself how fascinating Ichigo is and how he will formulate a plan to torment Ichigo. Byakuya then asks Mayuri why he didn't go to the Human World as well. Mayuri merely replies that there are multiple more interesting specimens in Hueco Mundo and will simply use the Garganta after the war to study the Living World more. Byakuya then suggests that Mayuri has faith in Ichigo's abilities to end the war.
Mayuri oversees the checking of the pillars to determine if they are all free of anomalies. As check is completed he initiates the activation of the world shifting bond posts. He is interrupted by one of his subordinates who tells him that he needs to wait as there are Shinigami in the town and a material world transfer without the aid of a Senkai gate is dangerous. Mayuri decides that he will give them time and count to ten as his subordinate calls for every Shinigami to get out of town before they are killed. Later, Mayuri begins doing regular research in Hueco Mundo.
Zanpakutō Unknown Tales arc (anime only)
Note: Events occurring in this arc are only in the anime and do not constitute canon material.
Click "show" to read the arc plot.
Captain Kurotsuchi is in attendance on Sōkyoku Hill when an emergency meeting of many ranking Shinigami is called. However, he openly complains about the Captain-Commander ordering the meeting at such a late hour. When Muramasa makes himself known to the Shinigami, he announces that Captain Yamamoto is no longer there. Captain Sajin Komamura is disturbed by this news and attacks Muramasa, only to see his own Bankai go rogue and attack him instead. Witnessing this turn of events, many captains and lieutenants attempt to release their own Zanpakutō, but fail. Upon inspecting his own katana, Kurotsuchi notes that he can no longer feel its Reiatsu. As President of the Shinigami Research and Development Institute, he is intrigued by Muramasa's powers and eagerly asks what he has done to accomplish such a feat. Muramasa flatly explains that he has cast a spell which "freed" the Zanpakutō Spirits from their "prisons." Shortly thereafter, Ashisogi Jizō materializes out of thin air in front of a dumbfounded Mayuri. But after a brief inspection of the spirit, the captain appeared relaxes, wearing a contented smile, a feeling not shared by any of the others present.
Later, while experimenting on himself, Mayuri discovers that the Zanpakutō have become completely different entities from the Shinigami. After experimenting on the captured Zanpakutō Spirit, Gegetsuburi, he discovers that if a Shinigami defeats or kills their respective Zanpakutō, the Zanpakutō will return to them, but if it is defeated by somebody else, it will not. If it's killed by someone else, it will revert to Shikai form, break in half. After the Zanpakutō Spirits and Captain Byakuya Kuchiki attack the Sixth Division's headquarters, Kurotsuchi arrives and detonates Ashisogi Jizō as it is restrained by Kenpachi, effectively subduing his Zanpakutō. As Kurotsuchi attempts to "treat" Ichigo of Ashisogi Jizō's poison, Unohana appears to take over from the fellow captain. He explains that he will use the broken Zanpakutō to learn about how Muramasa's brain-washing technique works. Later, Kurotsuchi completes his analysis of Muramasa's powers and begins undoing the brainwashing of the Zanpakutō Spirits, allowing the freed ones to rejoin their Shinigami partners in the Real World to fight Muramasa.
Beast Swords arc (anime only)
Note: Events occurring in this arc are only in the anime and do not constitute canon material.
Click "show" to read the arc plot.
During everyone's rest and partying from the recent chaos, strange beings appear at the Kuchiki Manor and cause much destruction. After killing one of them, Byakuya and Rukia go to Kurotsuchi for answers. Mayuri reveals that he never stated that the Zanpakutō Spirits would be returned to their original state. He calls out a restored Ashisogi Jizō to show that they can still be summoned. He explains that several of the spirits that Muramasa manifested were not recaptured and were able to kill their masters. Kurotsuchi goes on to say that rather than dying with their partners, they changed into new creatures he deemed "Tōjū". After warning them that these rogue spirits can access their full power, equal to a Bankai, at any time, he asks them with great delight to bring back one, alive, for him to analyze. Later, Rukia succeeds in capturing one and has it sent to Kurotsuchi, who responds with great glee. Despite his joy in analyzing them, he holds no interest in actually reversing the process from Tōjū to Zanpakutō, until he feels obligating by accepting various sweets as a bribe from Lieutenant Nanao Ise. As he begins his research, he notices something about the broken Tōjū sword that catches his interest. Mayuri later accompanies the staff of the SDRI on field research. Upon their return, they discover that the SDRI's buildings have been ruined by Senbonzakura and Zabimaru, greatly annoying Mayuri.
Gotei 13 Invading Army arc (anime only)
Note: Events occurring in this arc are only in the anime and do not constitute canon material.
Click "show" to read the arc plot.
Mayuri is called to Yamamoto's office, where the Captain-Commander asks for his opinion on the missing lieutenants. He then explains that they have to be in the Human World, as there is no record of them returning via the Dangai. Mayuri becomes infuriated when Hitsugaya implies that the 12th Division's S.R.D.I. missed something. When Lieutenants Nanao Ise and Rangiku Matsumoto are confirmed to have returned, in which they believe that only three hours have passed since their disappearance, he realizes that Hitsugaya is correct.
Captain-Commander Yamamoto then calls an emergency captains meeting, where Mayuri Kurotsuchi explains that there is a gradually expanding time-gap between the Human World and Soul Society. Mayuri then requests for a study to be made in this new phenomena to identify its cause, which is concerning him. Yamamoto places Mayuri in charge, whilst 11th Division Captain Kenpachi Zaraki is assigned for security. In the Dangai, Mayuri berates Akon on the lateness of the connection, explaining that the cause of the disturbance is indeed man-made. Mayuri shouts at Yachiru and Kenpachi to be quiet. As Nemu's survey equipment starts fluctuating, as a bright light erupts from the Dangai wall, enveloping Mayuri and the other Shinigami.
Mayuri later appears with other members of the Gotei 13 after they escape from the Dangai. He tells Inaba that for an underling, he pulled off a pretty big stunt. Inaba smiles and gets excited that he is there. Mayuri then says that he will make Inaba pay a million times over. After Inaba flees, Mayuri joins other members of the Gotei 13 in Ichigo's room for a meeting. Mayuri states that Inaba is the 7th seat of his division and the head of Dangai research in the S.R.D.I. He then explains that Inaba manipulated the Kōtotsu so that it would intercept them as they entered the Dangai in order to confine them while he replaced them with Reigai. He outlines the danger Inaba presents to the integrity of the Gotei 13, as Ichigo speculates why Inaba tried so desperately to capture Nozomi. Mayuri presents the conclusion that he may have placed something inside her body, akin to the Hōgyoku previously sealed inside Rukia's Gigai.
As Inaba calls forth his Reigai to protect him, Mayuri, disguised as his Reigai arrives. After Inaba backs off, Mayuri stabs him in the back, revealing himself to his subordinate and taunting him. Mayuri later reveals that when the Reigai lieutenants enter the Human World, Mayuri hides in the Dangai and defeats his Reigai counterpart with a surprise attack. He then posed as the Reigai through the use of contact lenses and a Reigai bracelet, infiltrating Soul Society. As he stabs Inaba, a though process interrupting drug is injected into his system. Mayuri uses his extendable arm to grab his neck and tie him up. Inaba manages to free himself from Mayuri's arm, prompting Mayuri to praise his combat ability. Mayuri reveals that he was stalling for time and offers to keep his eyes closed as he walks towards Inaba so that the later may attack him. Inaba does not attack and Mayuri stabs him once he is close enough. He explains about the drug to Inaba, who is confused about how he can move his body, but yet was unable to avoid Mayuri's simple attack.
As Mayuri torments Inaba, Suì-Fēng demands that he hurry up and finish him off. The Reigai of Isane Kotetsu comes to Inaba's aid, forcing Mayuri back. However, Inaba attacks and defeats the Reigai, prompting Mayuri to comment that his emotions have gotten the better of him now that he cannot think clearly. Inaba grabs the Mod-Soul pill from the remains of the dead Reigai, surprising Mayuri. Hitsugaya asks if it is a Gikon, but Mayuri reveals that it is a Modified Soul. Inaba swallows the pill and is ejected from his body, which he reveals to be a Reigai. Mayuri theorizes that he forced the Modified Soul he swallowed to take the effects of the drug. He forces Mayuri back and the Reigai return to his side. Inaba claims that he was the one who developed the Mod-Souls, which Mayuri dismisses as a lie. Inaba angrily decries this and reveals how advanced the research into Modified Souls was. He destroys the Reigai Reiatsu-limiters, prompting them to release their full power as several Reigai that had already been defeated appear. Mayuri explains that as long as their core form, the pill, is preserved, their bodies can be replaced. Inaba tells Mayuri that not even he could create Reigai that could withstand such Reiatsu. The Reigai engage in a grand melee with the captains. Mayuri is then intercepted by the Shikai of Reigai-Sajin Komamura. Eventually, Mayuri and the other captains are forced to retreat. Later, they return in time to help Ichigo and Kisuke against their Reigai pursuers.
While the other captains engage the enemy, Mayuri stays on the sideline, hoping that the Reigai won't be damaged too much so he can study them later. Reigai-Unohana soon insults him for not joining the fight. This prompts Mayuri to have an "active test" on her, as he always disliked the real Unohana. He is intercepted by Retsu-Unohana's Shikai and then captured by a "Sajō Sabaku" spell, only for him to cut off his arm and start regrowing it. While Mayuri laughs at Reigai-Unohana's failed attempt, Reigai-Kenpachi attacks from behind and slices off his other arm, causing Mayuri to collapse in shock. Later, it is revealed that Mayuri faked his death and liquefied himself to escape the battle. He then goes to join Kisuke and helps him defeat the Reigai-Kisuke.
The Lost Substitute Shinigami arc
Mayuri is one of two captains who didn't come to the meeting at First Division barracks.
The Thousand-Year Blood War arc
Mayuri is at the SRDI, while in an emergency situation. More and more Hollows keep disappearing and that Kurotsuchi claims to know who the culprit is. Akon asks Mayuri if it's the certain group he's thinking about and Mayuri confirms that it's only "them" who could do this. Later, Mayuri and Akon attend the captain's meeting, where they explain about the Wandenreich's infiltration in Soul Society and confirm that they are Quincy. Before he can finish his explanation, he is interrupted by Yamamoto, asking him the location of the enemies' headquarters. When Mayuri states that they still don't know, Yamamoto asks all of the captains to prepare for battle.
Mayuri confirms that he ordered his Division to kill 28,000 Rukongai citizens to correct the balance of souls. Yamamoto asks why he did not attain permission, noting that given the seriousness of the situation, he would have attained it. Mayuri responds that he would have had to take responsibility if things got worse. Yamamoto states that the situation would not have been so bad if the SRDI had reported the problem sooner. This prompts Mayuri to remind Yamamoto that he had dismissed Mayuri's warning when Uryū Ishida entered Soul Society and states that the Captain-Commander is responsible for the current events as he failed to kill "that man" a thousand years ago.
After the Wandenreich invade Seireitei, an angry Mayuri receives word from Rangiku Matsumoto that the enemy has the ability to steal Bankai. He curses his fellow captains for not waiting until he had completed his analysis. Mayuri is later notified via transmitter swords along with the other captains and lieutenants by Rin Tsubokura that Ichigo is currently heading to Soul Society, and comments that Akon must have acted on his own accord again. Some point afterwards, he and several other members of the Gotei 13 are surprised to sense Yamamoto's Reiatsu resonate throughout Seireitei as their Captain-Commander enters the front lines. Mayuri and other members of the Gotei 13 are then later surprised to detect Ichigo Kurosaki entering Soul Society.
After the enemies leave Soul Society, Mayuri requests for Ichigo to meet with him regarding his Zanpakutō, Zangetsu. As the captain explains to the Substitute Shinigami that usually it is impossible for a Bankai to be restored once broken, he explains that he did not fix his own Zanpakutō, but remodeled it. After quieting Kon, he learns that the Zero Division has arrived and brings Ichigo to witness their arrival.
When Senjumaru Shutara later brings a number of orbs to the Royal Guard's Tenchūren, Mayuri notices Tensa Zangetsu in one of them. He asks Senjumaru if she broke in to his lab, but she states that she simply placed her hand on the door and it opened, noting that the lock was easy to open. Kon then appears, acting as a projector for a communication system installed by Urahara to talk to Ichigo from Hueco Mundo. Both annoyed to see Urahara and intrigued by how the former captain modified Kon, he grabs the Mod Soul, applying much pressure to his eyes, prompting Urahara to, noting he has found the switches, state he has already turned them off. At some point, Mayuri and Nemu stabilize a grievously wounded Izuru Kira and prop up his damaged torso with thick rods.
After the Royal Guard leave, Mayuri and Nemu return to the SRDI and lock themselves in his room, with all the surveillance bugs inactive. They begin reviving a dead Arrancar, which a spying Akon and Kuna are completely shocked by.
During the Wandenreich's second invasion, Mayuri and Nemu finally emerge from within their room and find the SRDI completely transformed. Confirming Askin Nakk Le Vaar's explanation of the nature behind the shadows, Mayuri goes on to explain that in the time between the invasions he and Nemu had created a room completely without shadows, including their attire. Responding to the Sternritter's doubts of their intellect, Mayuri assures him that he'll be able to find the answer before going home.
Askin suddenly decides to retreat. When questioned, Askin responds that he doesn't want to spend time figuring out different strategies to get Mayuri to die. Mayuri decides to let him leave, preferring to analyze his Reiatsu and not get lured into Askin's territory. Mayuri then senses Suì-Fēng dealing a hard blow to her opponent. Askin responds by saying that, as his majesty expected, the captains who had their Bankai stolen found new ways to fight. Mayuri points out the implications of Askin's statements, saying that Yhwach anticipated this. Askin confirms this suspicion and admits that the captains are powerful.
Mayuri later notices how the Reiatsu of two captains had disappeared, and one of his subordinates confirms that it was Hitsugaya and Suì-Fēng. As he states that he is the only one who can fight the Quincy without Bankai, he is contacted by Kisuke Urahara, who informs Mayuri that he has found a way to recover a stolen Bankai. 
As Mayuri listens to Urahara saying that he has found a weakness in the Quincy's Bankai stealing, he gets angry that Urahara has installed a communications device in his clothes without his knowledge. When Mayuri tries to deactivate the device, Urahara suddenly arrives through a Senkaimon. Urahara proposes that the two cooperate, and Mayuri reluctantly agrees. Urahara then explains that an Arrancar's Resurrección is similar to a Bankai and therefore the Wandenreich should also be able to steal them, but they have not done so. Mayuri then concludes that either the Wandenreich can't steal a Resurrección or there would be a demerit for the Quincy in doing so, and that the latter is more likely. Mayuri then speculates that Quincy are particularly vulnerable to Hollows, so vulnerable that only being near a Hollow would be extremely dangerous to them. 
After the Sternritter activate Quincy: Vollständig, Mayuri comments on how things have gotten troublesome. He is then surprised when Urahara receives a call from Ichigo.
When Giselle Gewelle explains that she can turn Shinigami into her zombies without them having to die first, Mayuri appears and remarks that her power is interesting. When Giselle asks him who he is because she cannot see through the shining of his clothing, Mayuri says all great opponents shine brightly. Upon seeing Giselle abusing Bambietta, Mayuri dims the light from his outfit and states he did so to allow common people to look at him. Annoyed at being called a common person, Giselle has Bambietta unleash a flurry of bombs at Mayuri, who has Nemu pull him away. Mayuri has Nemu unleash several spherical devices with a timer of three seconds that collide with the bombs, but do not explode. When the devices explode, Mayuri explains how they are Reishi fixers that deactivate Reishi for a set amount of time before noting it is a simple mechanism. Upon learning of this, Giselle summons several zombified Shinigami. Noting he cannot strike them down because he knows them, Mayuri states he will leave this to those who are not familiar with the Shinigami as the resurrected corpses of Dordoni Alessandro Del Socaccio, Cirucci Sanderwicci, Luppi Antenor, and Charlotte Chuhlhourne emerge from the building behind him.
When the Arrancar begin arguing with each other, Mayuri pulls out a trigger and presses it, delivering an electric shock to their brains while telling them to stop talking. After shocking them a second time for talking once more, Mayuri explains how it will not affect their bodies before noting them coming out so robust makes it worth taking them from Szayelaporro Granz's laboratory. As the Arrancar rush into action, Mayuri tells Ikkaku and Yumichika that those who go against the Seireitei must die, as these were Yamamoto's words. When Giselle summons a zombified Tōshirō Hitsugaya, Mayuri notes this is bad.
After Hitsugaya critically injures Ikkaku and Yumichika, Mayuri notes his body is moving the same way it did when he was alive. Dodging Hitsugaya's subsequent attack with Shunpo, Mayuri theorizes that Hitsugaya was made into a zombie before he died because he cannot speak or act on his own like Bambietta can. Giselle confirms this and explains how those who are zombified before death can be completely controlled because they have no free will. Mayuri asks her what fun there is in controlling someone with no free will, only for Giselle to state she does not know because she is not a sadist. When Charlotte confronts Hitsugaya and attacks him, Mayuri yells for him to get back, only for Hitsugaya to slash Charlotte across the chest. However, Mayuri protects Charlotte from Hitsugaya's next attack with a Kidō barrier and states he will punish him for attacking someone he could not defeat by leaving him on the verge of death. Turning to Hitsugaya, Mayuri notes he cannot have him killing all his test subjects before realizing there is no point in trying to reason with Hitsugaya. Mayuri proclaims he does not like having such cruel things occurring to his test subjects without his consent and reveals he has many drugs which he wishes to try out on Hitsugaya before stating it will all be for the sake of the Seireitei.
Hitsugaya attacks Mayuri, who dodges and unleashes a Kidō net from his sleeves. When Hitsugaya attacks him again, Mayuri blocks with his sword and continues to parry the rapid attacks, explaining that he recently equipped Ashisogi Jizō with a sensor that allows it to constantly parry all swords which are 2 feet from him. When Hitsugaya attempts to knee him, Mayuri blocks the attack with a cloth and points out how he expected this as the cloth explodes, severely damaging Hitsugaya's leg. Hitsugaya blocks Mayuri's subsequent attack and activates his Bankai, Daiguren Hyōrinmaru before slashing the 12th Division captain down the torso and impaling him through the chest. However, Mayuri appears unharmed seconds later and asks the same question about his drugs. Hitsugaya quickly activates his Bankai and freezes Mayuri solid. However, Mayuri once again appears unharmed and asks the young captain about taking his drugs. Hitsugaya demands to know what is happening, prompting Mayuri to reveal Hitsugaya is experiencing a drug that takes him to the past every time he kills Mayuri. As Hitsugaya falls to the ground, Mayuri explains how the drug immobilizes the user for thirty seconds after they go back in time ten times. As Mayuri attacks him, he asks if Hitsugaya knows when the drug was administered.
Impaling Hitsugaya with his Zanpakutō, Mayuri releases his Shikai, paralyzing him. While he laments on how sad it is to use a drug such as the one he's about to use on a defenceless individual, he notes how Hitsugaya screaming for him to stop makes it a little easier. He administers the drug to Hitsugaya, who begins screaming intensely. The zombies of Rangiku Matsumoto, Rōjūrō Ōtoribashi and Kensei Muguruma arrive to attack him, only for Mayuri to respond by summoning the Arrancar.
After Kensei and Rose collapse from the effects of the Precognition Drug, having been exposed to it via the blood of the Arrancar, Mayuri injects them with the same drug he used on Hitsugaya, causing them to scream in agony. Mayuri turns his attention to Giselle and theorizes that Giselle needs to use more blood to zombify captain-class combatants because of how powerful their Reiatsu is before asking her if he is right. When Giselle does not respond, Mayuri explains how he developed a drug using blood samples of Gotei 13 members that replaces all of the blood inside of someone's body with blood which he has developed, prompting Giselle to express confusion. Deciding to simplify his explanation, Mayuri reveals that the drug allows him to take control of her zombies, shocking Giselle. As Kensei and Rose stand up behind him, Mayuri bids Giselle farewell before having Kensei stab her through the heart. Soon afterward, after Kensei and Rose incapacitate Shūhei Hisagi and PePe Waccabrada, Mayuri arrives and explains the situation to Byakuya. When PePe attempts to take control of Kensei with The Love, only for Kensei to punch him in the face, Mayuri reveals The Love will not work on his zombies because they do not know the meaning of love.
Later, after the Soul King is killed and Ukitake initiates Kamikake to prevent the destruction of the realms, Mayuri arrives at his laboratory, which has been modified by Urahara for his own purposes, and notes that the Shinigami have changed it quite a bit. Having heard Nanao's explanation of how they will not be able to form doorways to the Soul King Palace with their current total amount of Reiatsu, Mayuri reveals a Reiatsu amplifier behind a wall and tells them to use it to make up for the deficit.
After the arrival of Aizen and he subsequent attempt to bring down the Soul King Palace, his dense Reiatsu merely dissipates in a massive cloud, Kyōraku informs him that the chair is among their greatest achievements as it allows them to cap his Reiatsu. Mayuri steps forward and alerts Aizen to the fact that he created the chair that he now sits in. Mayuri insists that Reiatsu is something that will always be created so long as a Shinigami's heart continues to beat and since the prisoners in Muken cannot be killed, he had to create something that could keep Reiatsu in check and not to cancel it out completely. He begin to mock and chastise Aizen for thinking he could overcome his technology. Aizen challenges to pit his Reiatsu against Mayuri's technology but is interrupted by the arrival of NaNaNa Najahkoop.
Mayuri and Nemu arrive in the newly transformed Royal Realm, but his relief at being able to operate on his own is short lived when he realizes that Kenpachi Zaraki has ended up in the same location. The three race down a street when they run into Pernida Parnkgjas. Kenpachi asks aloud what Pernida is, causing Mayuri to mock and ignore him. However, when Kenpachi prepares to kill Pernida, Mayuri shouts at him to wait. After Kenpachi cuts Pernida and Pernida's head begins to swell, Mayuri wonders if a muttering Kenpachi is asking another question or talking to himself again.
Watching Pernida's head expand, Mayuri admits that he finds it creepy, to the surprise of Kenpachi. After Kenpachi rips his own arm off to prevent The Compulsory from warping the rest of his body, Mayuri commends him for making this split-second decision and attempts to explain a strategy for defeating Pernida without getting close, only for Kenpachi to rush in and cut Pernida anyway. However, when Pernida warps Kenpachi's legs, Mayuri steps in and stabs Kenpachi with Ashisogi Jizō before activating Fear Factor 4, causing Kenpachi to collapse. Mayuri proceeds to explain how The Compulsory is Pernida using its nerves to control its enemies' bodies before releasing a liquid over Pernida's extended nerves, causing it to scream in pain. Revealing that he has exposed its nerves, Mayuri wonders what drug he should test out on it.
Seeing Kenpachi moving his eyes, Mayuri notes he is a monster for being able to do this while under the effects of the paralyzing toxin of Ashisogi Jizō before thanking him for helping him discover both the nature of The Compulsory and a need to improve his Zanpakutō. Turning to Pernida, Mayuri claims that it should donate its body to him for experimentation in order to honor Kenpachi's sacrifice, but is surprised when Pernida rips apart its hood to reveal it is the left arm of the Soul King. After Pernida gains the rest of its body in the form of a large arm, Mayuri reveals that its Reiatsu is similar to that of Mimihagi and admits that it is not very odd for the left arm to have been on its own somewhere if the right arm was too. When Pernida attacks him with more shadowy tendrils, Mayuri defends himself with an unusual shield before claiming that his happiness outweighs his curiosity as to why the left arm of the Soul King is working for Yhwach. Ikkaku tells him to run and demands to know how he can be happy about this, but Mayuri enthusiastically states that he has a completely new subject to study and could not possibly be unhappy about it. As Pernida unleashes a barrage of tendrils, Mayuri tells it to show him more.
Pernida states its name once more, prompting Mayuri to claim he is the one who will name it because he found it before stating that he will make an exception this time. When Pernida sends its nerves into the ground, Mayuri notes this is proof that Pernida can control inanimate objects as well and leaps to avoid the ground rupturing underneath him before grabbing onto a building with Jabarakaina, but Pernida throws him off by pushing out the side of the building facing him before crushing him between two giant hands made of stone. However, Mayuri escapes unscathed by having his luminescent armor explode, and as he falls toward Pernida's nerves on the ground below, Mayuri presses something on the backs of his shoes, causing him to stop and float in midair on Reishi. Mayuri reveals this is the Quincy movement technique, Hirenkyaku, before admitting that this is only the name that Uryū and Sōken use for it. Deciding to take a sample, Mayuri blows off Pernida's pinkie with a remote explosive, causing it to scream in pain, before splashing it with a preservation fluid. However, Mayuri is caught off-guard when nerves extend from the pinkie into his arm, and as his arm bursts, Mayuri quickly stitches it back together while rearranging its anatomical structure before claiming that Pernida cannot take control of him so easily.
When Mayuri admits that he has not operated on his arm in a while, Pernida asks him if he is nervous as its severed finger grows into another hand that leaps toward Mayuri, who blasts it away. As Mayuri notes that it will be hard to take pieces of Pernida back if it keeps reproducing itself, Pernida removes its middle finger, which begins to grow additional fingers. Recalling how he once read that the right arm of the Soul King is responsible for "stopping" and the left arm is responsible for "advancing", Mayuri states that he never thought he would be able to prove this knowledge. When Mayuri unsheathes his Zanpakutō and activates his Bankai, Yumichika believes that he intends to poison Pernida, but Mayuri refutes this and claims that he now has enough information to give birth to "it" before revealing Konjiki Ashisogi Jizō: Matai Fukuin Shōtai. Explaining how this is a modified version of his Bankai that can give birth to other Konjiki Ashisogi Jizō, Mayuri has his Bankai create a Konjiki Ashisogi Jizō with visible veins across its body, which Mayuri reveals is a version with nerves on the surface of its body. Pernida attempts to take control of the Konjiki Ashisogi Jizō, but Mayuri explains how the nerves are divided into 70000 layers, which will peel off if taken control of, as the Konjiki Ashisogi Jizō devours Pernida and its clones.
Mayuri notes that Pernida would have multiplied within the Konjiki Ashisogi Jizō had it been bitten before expressing shock when the Konjiki Ashisogi Jizō is destroyed by Heilig Pfeil from the inside out. After dodging a Heilig Pfeil, Mayuri sees Pernida reminding him it is a Quincy and mocks the left arm of the Soul King saying such things, only to be surprised when Pernida's manner of speaking changes. Realizing that Pernida's speech has become more eloquent as their fight has progressed, Mayuri sees several incoming Heilig Pfeil and tries to avoid them, only for the nerves attached to one of them to infiltrate and destroy his left arm. As another Heilig Pfeil hurtles toward him, Mayuri is saved by Nemu, who grabs the arrow and cuts off her own arm. Moving Nemu and himself to a safe location, Mayuri berates Nemu for acting on her own judgement before stating that it would be incredibly difficult to create and raise another one of her.
Nemu hands Mayuri a flesh supplement with which to regenerate his arm and reveals that she rescued him in order to deliver it. After regenerating his arm, Mayuri is informed that he did not take any such drugs before the fight began like he usually does, causing him to note that Nemu really does watch him. Jumping off the tower he and Nemu are standing on, Mayuri presses the tops of his Hirenkyaku Shoes, causing them to begin propelling him forward toward Pernida. As he dodges Pernida's Heilig Pfeil, Mayuri sees the two clones of Pernida appear behind him and begin firing as well. Mayuri continues to dodge the arrows as he contacts Nemu, whom he informs of of his plan to stop Pernida by injecting it with a coagulating agent that will render it immobile and unable to function. As Nemu successfully injects the agent and paralyzes Pernida and one of its clones, Mayuri informs the remaining clone that this is the end, but is surprised when it simply rips off its infected thumb and informs him that this is not enough to kill it. Noting that it sounds like Kenpachi, Mayuri realizes that Pernida can evolve by absorbing information from objects which it touches with its nerves and deduces that Nemu's speed will not be enough to outpace Pernida if it has evolved to Kenpachi's level. Mayuri yells for Nemu to get out of the way as Pernida sheds its infected skin like the modified Konjiki Ashisogi Jizō could, which Mayuri recognizes.
As Pernida prepares to attack Mayuri, it is blown apart by Nemu, who bursts through it at high speeds while grabbing Mayuri. When a shocked Mayuri demanded to know why Nemu had this power, Nemu explains how she increased the power of her body at the cost of heightening the decomposition rate. Surprised by Nemu claiming that she is following her mission to protect him, Mayuri angrily states that her mission is to evolve, but Nemu merely states that she can best show the results of her growth by protecting him before throwing Mayuri onto a nearby building. Admitting that he did not ever think Nemu would have to fight in his place, Mayuri notes this is very humiliating.
When Nemu is torn apart by one of Pernida's clones, Mayuri is shocked to the point of having Szayelaporro Granz appear as a vision next to him. As Szayelaporro claims that this is simply a chance for Mayuri to create something better and that Pernida has crushed both his prized creation and his arrogant attitude, Mayuri disperses him and realizes what he must do before inviting the two remaining clones to eat what is left of Nemu. Snatching Nemu's brain away before it can be eaten, Mayuri repels one of the clones' nerves with his Reiatsu alone before telling them to keep eating before it dies as one of its fingers enlarges. As the other fingers follow suit, Mayuri explains how he replaced Nemu's regenerative cells with cells that multiply at high speeds and reveals they are controlled by the brain alone before revealing that the clone will die from excess regeneration as the clone's tissue is grossly expanded.
As the pieces of Pernida's clones fall to the ground and explode around him, Mayuri walks away with Nemu's brain in hand, only to collapse as his damaged legs give out from underneath him. Upon seeing Ikkaku and Yumichika have arrived, Mayuri admits he should be grateful that they did not interfere in his fight before revealing that he has managed to de-zombify Hitsugaya and Rangiku, who are located in body containers a few feet away. As he and Rangiku emerge from the containers and begin walking away, Hitsugaya thanks Mayuri, who is helped into one of the pods by Ikkaku and Yumichika. After placing Kenpachi in the other containers, Ikkaku and Yumichika thank Mayuri for saving Kenpachi before leaving as well. Mayuri notes the unusual amount of people who are thanking him today before claiming that he has finally beaten Urahara with Nemu's evolution as he falls asleep.
Ten years later Mayuri comments on how the construction of a section of the Seireitei is finally complete and he can now expand his secret underground network. He surmises that he will have to do an on-site inspection and calls his new assistant Nemuri Hachigō to come along to which she yells back that she is coming. He scolds her for yelling and comments how he doesn't know how she got that way. As the remnant of Yhwach's Reiatsu appears he is already at the site when he is joined by the arrival of Captains Byakuya Kuchiki and Suì-Fēng. He points out his surprise that they are there seeing as he doesn't recall informing anyone of the situation. Suì-Fēng tells him that he would be wise not to underestimate their espionage and information networks. Byakuya addresses the point that if Mayuri is already there it must mean their information is accurate, to which Mayuri states that whether the information is right or wrong they will all see for themselves soon enough. They then see the remnants of Yhwach's Reiatsu in front of them, and brace for an attack. However, just as the Reiatsu grows in strength it randomly vanishes without a trace, shocking the three captains.
As a leading researcher in Soul Society, Mayuri has developed a number of unique items. The notable ones are below:
Nikubakudan (肉爆弾, Flesh Bomb): Mayuri has developed biological bombs that he has implanted into the bodies of his own subordinates without their knowledge. By using a remote detonator he can set off the bombs which use every biological portion of the body causing devastating explosions that can seriously damage the surrounding area.
Hojiku-Zai (補肉剤, Flesh-mending Drug; Viz "Flesh-Healing Medicine"): Mayuri has also developed a "regenerative serum," which can regrow limbs upon injection, and looks like some sort of green chemical. He used it to regenerate his arm when he fired it off as a grappling hook, and complained about the side-effects of pain that the serum caused. It can also be used to heal less severe injuries, such as those suffered by Uryū and Renji.
Gigai Specialization: One major invention is present, which is Mayuri's lieutenant and so-called "daughter," Nemu Kurotsuchi, who is the ultimate result of his Gigai and Modified Soul research. The fact that Nemu can survive toxic poisons, a pierced lung, and having all of her nutrients robbed from her is a testament to Mayuri's own skill in Gigai creation and modification.
Bount Sensor: He has created a simple Bount sensor. Though not as powerful as Urahara's equivalent mod soul versions, it is far more effective once properly calibrated.
Zanpakutō Repair and Modification: Mayuri offers a catalogue of Zanpakutō related services that include repair and gender reassignment.
Data-gathering Bacteria (監視用の菌, Kanshiyō no Kin; lit. "Monitoring/Surveillance-Use Bacteria"; Viz"Surveillance Bacterium"): He also implants opponents that escape from battle with data-gathering bacteria so as to monitor them afterwards, as was the case with Uryū during their fight. This was how he was able to counter Szayelaporro's Teatro de Titere: using the information gleaned from the bacteria he had implanted within Uryū, Mayuri was able to quickly conceive and carry out an operation to safeguard himself and his lieutenant beforehand.
Fake Karakura Town: One of his greatest achievements is the creation of an exact replica of Karakura Town, as he and his division are the ones responsible for its creation.
Superhuman Drug (超人薬, Chōjin'yaku) Mayuri has manufactured a "superhuman drug" that can slow down a person's perception of time. The drug is kept in a blue bottle by him, but also inside Nemu's body. It is able to make one second seem like 100 years for the unfortunate victim to whom it is administered. An undiluted dose of the drug causes the senses to speed up trillions of times while the relatively "slow" body fails to keep up, resulting in paralysis; on the other hand, it is implied that a diluted dose of the drug can greatly enhance the user's reaction speed. He even stated that a single droplet would have to be diluted 250,000 times to be suitable for use.
Anti-Arrancar Mine (破面専用の地雷, Arankaru Senyō no Jirai; lit. "Arrancar-exclusive-use Landmine"): After rescuing Uryū from Szayelaporro, he gives Uryū a landmine he designed which is meant to be effective against Arrancar. Once its sensors pick up an Arrancar's Reiatsu, it detonates violently. Uryū subsequently used it on the Espada Yammy Llargo, with the effect of critically injuring the Arrancar in his sealed state; the explosion was very powerful.
Garganta Construct Device: Mayuri Kurotsuchi discovers this device among the many materials in Szayelaporro's laboratory after his defeat. Mayuri was able to create a perfect Garganta portal when using it. This includes the ability to close it in mid-transfer and has so far been only used once - To open a portal to the Human World, with Ichigo Kurosaki and Retsu Unohana being the first test subjects.
Thought Inhibitor Drug: Mayuri concocts a special drug which can stop thought processes from occurring within the brain. Stored in a purple vial, it can be injected into an individual via Mayuri's Zanpakutō. This drug restricts the individual's control over all motor functions, as is the case when Kagerōza Inaba is rendered unable to evade a simple attack from Mayuri. It also can cause the individual's emotions to go out of control. This drug causes the affected individual's eyes to glow with a purple tint.
Anti-Shadow Clothing: After realizing that the Wandenreich's invasion of the Seireitei had something to do with shadows, Mayuri created luminescent clothing for himself and Nemu to prevent the formation of shadows in his laboratory. His outfit is composed of a large robe with a spiked hood, and Nemu's takes the form of a form-fitting robe with a top hat. This clothing, which Mayuri refers to as Explosive Reactive Armor (爆発反応装甲, Bakuhatsu Han'nō Sōkō), will explode if Mayuri is crushed by an object, freeing Mayuri in the process and leaving him unscathed.
Reishi Kotei Sōchi (霊子固定装置, Spirit Particle Suspension Devices; Viz "Reishi Locking Device"): Mayuri has developed several spherical objects with a band circling the middle and a button on one side. When activated, these spheres cause any Reishi they come into contact with to cease all activity for a specific amount of time. This allowed Mayuri to counter Bambietta Basterbine's The Explode by delaying the explosion of her Reishi bombs by three seconds.
Postcognition Drug: Mayuri has created a drug that bestows upon its user a Past Forecasting/Predicting Power (過去を見通す力, Kako wo Mitōsu Chikara). Its effect causes the user to enter a time loop in their mind during a battle; whenever they kill Mayuri, they are sent back to a certain point in time and forced to battle him again, so the only way to exit the loop is to not kill Mayuri. However, because this drug affects the hippocampus section of the brain, which governs short-term memory, going back more than ten times will cause the user to experience complete bodily paralysis for thirty seconds due to the part of their brain that controls their sense of balance temporarily shutting down.
Blood Reorganization Drug (血液組成を改変薬剤, Ketsueki Sosei wo Kaihen Yakuzai): Using blood samples of Gotei 13 members as a base, Mayuri has created a drug that converts all of the blood within the body of the subject to blood which Mayuri himself has developed. He used this drug to counter the effects of The Zombie by converting Giselle's blood inside her zombies to his developed blood, allowing him to take control of her zombies and use them against her.
Reiatsu Amplifier (霊圧の増幅器, Reiatsu no Zōfukuki): Mayuri has created a machine that can amplify the users' Reiatsu, allowing them to make up for a deficit in their group should a powerful Shinigami leave. It is a large spherical device with an X-shaped lid on the front.
Reiatsu-restraining Material: In order to restrain the prisoners in Muken who, for one reason or another, cannot be killed, Mayuri has invented a material capable of restraining Reiatsu. Those imprisoned in restraints of this material have their Reiatsu limited to a small area around them. Mayuri can manipulate the level at which the Reiatsu can be used by the wearer of the restraints. This material is extremely durable, to the point where it can withstand a Hadō #90. Kurohitsugi cast by Sōsuke Aizen.
Hirenkyaku Shoes: Mayuri has created shoes that allow him to perform the Quincy movement technique Hirenkyaku by gathering Reishi in the air underneath them, which he activates by pressing a button on the back of the heel. Using these, Mayuri can float a few inches above the ground, thus rendering all attacks requiring him to touch the ground useless. By pressing a section on the top of the shoes, Mayuri can propel himself forward with a continual blast of energy from the bottom of each shoe, like a rocket; the speed he gains from this allows him to easily dodge dozens of Heilig Pfeil being fired from multiple angles in rapid succession.
Nerve Freezing Agent (神経凝固剤, Shinkei Gyōko Zai; Viz "Nerve Coagulating Agent"): A drug injected into the nerves of an organism which forcefully freezes any organs connected to those nerves; open eyelids will remain open, hearts will not expand or contract, and mouths will become unable to shut. The blood of the organism also coagulates, effectively killing the target. Once the drug begins to take effect, the victim's skin becomes dark in coloration. However, this can be countered if the target's skin is divided into multiple layers, which allows it to simply shed a damaged one and remain unaffected, as with Pernida Parnkgjas.
Powers & Abilities
Genius Intellect: Mayuri Kurotsuchi is the most intelligent, scientific, and inventive mind in Soul Society. According to Shunsui Kyōraku, if given a full day to prepare with enough information at hand, Mayuri can find a solution to any problem or obstacle.
Master Scientist/Inventor: As the head of the Shinigami Research Institute, Mayuri is a talented inventor and scientist, having created a number of devices and techniques to aid him in battle.
Master Chemist: Being the current head of the Research and Development Institute, Mayuri is an adept chemist.
Master Strategist: Mayuri has a talent for being well prepared. He takes many precautions before engaging in personal combat with an adversary, usually studying them through his various methods. He always has a contingency plan if something doesn't work out the way he expects.
Body Modification Expert: Mayuri has done extensive research on modifying bodies, and he has upgraded a variety of his own body parts to function as weapons and provide him with useful abilities. In addition, he can also restructure his own body in an extremely short period of time if necessary, such as when he rearranged the contents of his arm in order to prevent Pernida Parnkgjas from controlling it.
Nikushibuki (肉飛沫, Flesh Splash): When Mayuri stabs himself with his Zanpakutō while in its sealed state, it shifts him into a liquid form. Doing so doesn't kill him, as it is a last resort technique, but instead simply leaves him unable to attack or be attacked, making it an effective escape tool. He can move around and speak in this form. He reforms after a few days, but without any of his previous body modifications. This ability is a result of the extensive amount of experimentation he has performed on himself.
Jabarakaina (蛇腹腕, Snake Belly Arm): His left arm can extend out like a grappling hook. When the arm is attacked it explodes on impact, but with his regenerative serum, this is not a problem (though it does cause him serious pain).
Hidden Kusarigama: He is able to pull part of his ear out to form a scythe, attached to a rope-like ligament, for use as a kusarigama. It is easily as sharp as a standard Zanpakutō, and he is quite skilled in its use.
Nisehada (贋膚, False Skin): Another one of Mayuri's abilities, likely achieved scientifically, is his ability to meld with the color and texture of the environment. He used it while attempting to track the Ryoka in Soul Society. When he reveals himself, the topical camouflage flakes away.
Organ Replacement Surgery: Most impressively, he has demonstrated the ability to replace functional internal organs with false ones, a feat he performs on himself and his lieutenant to safeguard them from injury. This particular operation is conceived of and carried out in the span of less than an hour.
Tracking Expert: He has stated that he merely needs a strand of a person's hair to find them. By using a simple chemical process, he can discern the location of the person in question, using their DNA as a reference.
Zanpakutō Modification Expert: Uniquely among Shinigami, Mayuri can manually alter and improve his own Zanpakutō and its capabilities. When fighting Szayelaporro, Mayuri revealed that he had installed a self-destruct feature in his Bankai that would activate should it attack him. During his skirmish with a zombified Hitsugaya, he displayed the use of a sensor installed in the hilt of his Zanpakutō that allowed it to automatically counter all sword attacks aimed toward him. After paralyzing Kenpachi with Ashisogi Jizō, Kyōdo Yon in order to incapacitate him, Mayuri noted that he would have to upgrade the paralyzing power of his Shikai after seeing that Kenpachi could still move his eyes. Most notably, however, Mayuri used the information he gained on Pernida Parnkgjas during their battle to create an alternate form of his Bankai in order to counter the latter's The Compulsory.
Arrancar Resurrection: Mayuri has found a way to bring deceased Arrancar back to life with their personalities and fighting skills intact; he can also fully restore any body parts they lost in death, such as with the revived Luppi Antenor, who lost the upper half of his body to Grimmjow Jaegerjaquez. However, these resurrected Arrancar are not innately loyal to Mayuri, so he keeps them in line by electrically shocking the pain centers in their brains. He has also integrated his Postcognition Drug into the bodily fluids of all his resurrected Arrancar, so if their opponents come into contact with these fluids, they will experience the effects of the drug.
Expert Swordsman: While not as proficient in swordsmanship as some other captains, Mayuri is skilled enough to hold his own in a fight. His expertise with his Zanpakutō lies in his effective use of its abilities while in either Shikai or Bankai, rather than his swordsmanship skill. He relies on those abilities, or his pre-planned strategies, rather than actually engaging in melee combat with his opponent. Mayuri seems to be ambidextrous, as he wields his Zanpakutō in his right hand and his scythe-ear in his left (often simultaneously). During the Bount Invasion, he briefly wields his Zanpakutō left-handed as well.
Kidō Expert: According to Shunsui Kyōraku, Mayuri is one of the most proficient Kidō users in Soul Society. He can release a destructive form of Kidō silently from the palms of his hands, blasting holes through walls, and instantly create Kidō barriers to protect others.
Shunpo Expert: Mayuri is able to easily outmaneuver Uryū Ishida's use of the Quincy Hirenkyaku technique to set up a surprise attack. Mayuri points out that Shunpo can counter Hirenkyaku but that it's very tiring for him. He was not fast enough to outmaneuver with Uryū when he entered the Quincy: Letzt Stil, making him at least an expert in the technique. He dodged a close-range attack from Tōshirō Hitsugaya by moving behind him almost instantaneously.
Great Spiritual Power: As the captain of the 12th Division, Mayuri boasts a great amount of spiritual power. He is noted to having amazing spiritual pressure that comes in waves. His Reiatsu is pink.
Enhanced Endurance: Mayuri has a high tolerance towards pain and damage. In his fight against Uryū Ishida, he survived having almost half of his body blown off.
Ashisogi Jizō (疋殺地蔵, Leg-Cutting Jizō; Viz "The Leg-Cutting Guardian"): Mayuri's Zanpakutō's guard is wrapped in cloth, and has several spiky protrusions sticking out right below the blade, which appear to resemble leaves. The hilt is pink. Unlike most Shinigami, his Zanpakutō's sheath hangs directly in front of him, instead of to his side as they are commonly worn, through a visibly modified hook on the end of the hilt of Ashisogi Jizō. At some point during the Quincy Blood War, Mayuri installed a sensor in Ashisogi Jizō that causes it to automatically block all sword attacks within two feet of his body at an angle of sixty degrees or greater.
Shikai: Ashisogi Jizō's Shikai command is "Rip" (掻き毟れ, kakimushire; Viz "Claw Out"). Ashisogi Jizō's blade glows and transforms into a deformed trident with curved, serpentine blades. The middle blade is straighter and longer than the side blades, and appears to ascend from the guard, which is shaped like a baby's head with hands clasped in prayer (as Ksitigarbha is depicted), all mounted on his sword's normal hilt, which has more ornate spiky protrusions on either side, which resemble golden leaves right below the guard. The baby's mouth secretes a poisonous vapor in this form at various intervals.
Shikai Special Ability: The weapon works like the venom of a spider bite; when an opponent is stabbed by Ashisogi Jizō, it severs the brain signals controlling the neural impulses for movement in the limbs of the victim, regardless of where they were struck. But, unlike regular paralysis, the pain receptors and nerve endings are unaffected by the weapon, so the victim can still feel pain, even in a paralyzed limb. Healing the stab wound does not immediately remove the inflicted paralysis.
Ashisogi Jizō, Kyōdo Yon (疋殺地蔵 恐度四, Leg-Cutting Jizō, Terror Magnitude 4): Mayuri sticks his finger in one eye of the baby's head, causing it to begin leaking a dark fluid while the baby opens its mouth to scream. Anyone not of Mayuri's blood who hears the scream for 4 seconds will be paralyzed. In contrast to Ashisogi Jizō's initial ability of only stopping the neural impulses of movement, this technique completely paralyzes everything biological.
Bankai: Konjiki Ashisogi Jizō (金色疋殺地蔵, Golden Leg-Cutting Jizō; Viz "Divine Leg-Cutting Jizō"): The baby's head on the guard opens its mouth as it produces a giant creature with the body of a caterpillar in a red cape, with a grotesque golden baby's head and arms, and a silver halo hovering around its head. Near the back of the halo are 4 bells, 2 on each side. While in this form, his Zanpakutō returns to its sealed state. It emits its own red Reiatsu upon release. In this state, the creature seems to follow Mayuri's verbal commands. While using his Bankai, Mayuri's Reiatsu turns red. Mayuri achieved Bankai with the fifth Nemuri he created, which he used to modify his Zanpakutō.
Bankai Special Ability: The creature breathes a poisonous derivative of Mayuri's blood, which is lethal to anyone who breathes it, aside from Mayuri and Nemu. The poison spreads through an area of about 200 meters around Konjiki Ashisogi Jizō, and it is almost impossible to avoid. The poison of Konjiki Ashisogi Jizō poison is very potent, as Szayelaporro's body started to break down immediately after it was introduced. The poison has an antidote, which Nemu keeps behind her lieutenant's badge, and which Mayuri keeps on his person. Mayuri can change the composition of the poison as well, ensuring that no foolproof antidote can ever be manufactured to cure it, and no immunity is developed against it. Even if the opponent does not breathe, the poison will still enter their body.
Retractable Blades: Konjiki Ashisogi Jizō can produce numerous blades which extend from its chest, allowing it to run through and skewer opponents. This, when used simultaneously with its poison, makes Konjiki Ashisogi Jizō particularly lethal to anyone that cannot keep a safe distance, which is in turn difficult due to its immense size. In addition to creating blades, it can also apparently devour an opponent after it charges into them, killing them.(Unnamed)
Self-Destruct Protocol: Mayuri has also physically modified Konjiki Ashisogi Jizō itself so it will self-destruct and return to its sealed state if it attacks him.(Unnamed)
Modified Bankai: Konjiki Ashisogi Jizō: Matai Fukuin Shōtai (金色疋殺地蔵: 魔胎伏印症体, Golden Leg-Cutting Jizō: Demonic Womb Covering Seal Symptomatic Body; Viz "Demonic Recumbent Womb"): When necessary, Mayuri can unleash a modified form of his Bankai. This takes the form of an enormous, heavyset, purple-skinned baby dressed in a golden loincloth and with golden fabric covering its pectorals. It has a misshapen head with completely white eyes, which is adorned with two branches of a balancing scale holding up large boxes, and its belly has a large vertical gash in the center with kanji written on either side. The baby rests on a large pile of thick umbilical cords with visible veins.
Modified Bankai Special Ability: Konjiki Ashisogi Jizō: Matai Fukuin Shōtai can create modified versions of Konjiki Ashisogi Jizō with the information and data Mayuri sends to it; this allows it to counter specific abilities of Mayuri's opponents.
Konjiki Ashisogi Jizō (Surface Nerves): When fighting Pernida Parnkgjas, Mayuri had his modified Bankai create a Konjiki Ashisogi Jizō that had nerves on the surface of its body, which, though causing it intense pain simply by coming into contact with the air and ground, allowed it to effectively resist Pernida's The Compulsory because its nerves were divided into 70000 layers, each one of which would peel off if Pernida's nerves entered it.
Poison Repelling/Reiatsu Repellent (Bankai): It is possible for a person to remain unaffected by the poison by repelling it with a sufficient amount of Reiatsu. Anyone within the vicinity of the person repelling the poison will also be unaffected.
In Bleach: Brave Souls, several different versions of Mayuri are playable. His Thousand Year Blood War arc version draws from his appearance during the battle against Pernida Parnkgjas, where he moves around with his Hirenkyaku Shoes. In this form, Mayuri is a melee character with the "Shinigami Killer" ability who can inflict Paralysis with every attack, and his special attack is Matai Fukuin Shōtai (魔胎伏印症体, Demonic Womb Covering Seal Symptomatic Body), which unleashes a new Konjiki Ashisogi Jizō from his modified Bankai that attacks his enemies, inflicting immense damage.
Some games also have him with Nemu as an assist character.
Mayuri features on an edition of the Fourth Session of Bleach Beat Collection, where Ryusei Nakao performs two of the three tracks as Mayuri: "Not Perfect is Good" and "12," the latter of which is a duet with Nemu.
Mayuri features in the third volume of Bleach "B" Station's second season and volume three of season four.
The four 12th Divison members being killed by the bombs set by Mayuri is drastically toned down in the anime. In the manga, after the first explosion, organs can be seen flying through the air, splattering blood on the remaining three squad members. The body of the squad member expressing confusion to Mayuri was shown imploding before him and the other two 12th Divison members are engulfed in the second explosion. In the anime, the organs weren't shown, and the confused squad member's body didn't implode and was simply engulfed by the second explosion. 
When Mayuri uses his Jabarakaina, blood is shown coming from his arm. In the anime however, the blood isn't visible.
The process at which Mayuri's Hojiku-Zai restores his arm in the anime differs from the manga. In the manga, his arm goes through a reformation process. In the anime however, Mayuri's arm simply grows back, glowing with Reiryoku.
Mayuri stabbing Uryū with Ashisogi Jizō is toned down in the anime. In the manga, Mayuri stabs Uryū's arm and removes it, while in the anime, Uryū's arm isn't shown being stabbed, and Ashisogi Jizō isn't shown being removed from the latter's arm.
In the anime, after stabbing Uryū with Ashisogi Jizō, and remembering that Nemu is paralyzed, he attempts to stab her with his Zanpakutō, instead of stomping on her again like he did in the manga.
Mayuri after being shot by one of Uryū's Quincy: Letzt Stil arrows was drastically toned down in the anime. In the manga, Mayuri was engulfed in flames and was missing his left arm and shoulder, his left pupil, and a portion of his left side. In the anime however, he was only missing most of his left arm.
Mayuri after being grievously wounded after Uryū destroyed Konjiki Ashisogi Jizō was drastically toned down in the anime. In the manga, bone remnants were shown in the hole in Mayuri's body, whereas in the anime, the remnants are not visible.
When Mayuri performs Nikushibuki and starts to liquefy, his eyeballs aren't shown in the anime as they are in the manga.
The small, slatted portcullises with multiple earrings in place of where Mayuri's ears would be aren't visible in the anime as they are in the manga. Instead, they are obscured by strands of Mayuri's hair. Also in the anime, the scars that are on his lower body are not shown, leaving the ones on his upper body visible.
Mayuri runs a cosmetic surgery clinic called Charismatic Dr. Mayuri Kurotsuchi's Magical Clinic (カリスマDr.[ドクター]涅マユリの マジカル☆クリニック, Karisuma Dr.[Dokutā] Kurotsuchi Mayuri no Majikaru Kurinikku).
Kurotsuchi's last name is one of the few Shinigami names in Bleach which uses kanji based on the meaning of the name and not the sound. "Kurotsuchi" means "black soil" (kuro - black; tsuchi - soil), as does the kanji (涅). However, the kanji's reading (pronunciation) is "ne" or "so".
Tite Kubo has stated in an interview that Mayuri is his favorite character to draw.
According to the Bleach: Official Character Book SOULs, Mayuri's Zanpakutō has the ability to turn whatever it cuts to liquid. However, this has yet to be shown in the manga or the anime.
In its manga debut, Konjiki Ashisogi Jizō appeared to be wielding a sword. However, any time Mayuri has subsequently activated it, the sword has been missing.
He writes a surprisingly popular serial article for the Seireitei Communication titled Medicine for the Brain (脳にキく薬, Nō ni ki ku Yaku) which has information about the practical uses of medicine as well as detailed reports about nearly every experiment he undertakes.
In manga, one of the four 12th Divison members was killed in the first explosion caused by the bombs set by Mayuri, before the other three were killed in the second explosion. In the anime however, three of the four members were killed in the first explosion instead, leaving only one member being killed in the second explosion.
(To Orihime Inoue) "If you work for me, I'll treat you well. In case you are worried, I am really gentle with female subjects. How about this? I'll give you top class special treatment. I'll only drug you eight times a day and only four hours of machine operations a day. You will eat with your mouth and when you sleep, I'll give you clothes. And I'll stay away from any life-threatening operations if I operate on you. How about it? This is a special offer that I've never offered to any test subject before."
(To Uryū Ishida) "Ooh, a Quincy. They are a rare breed. I haven't seen a live one for many years. However, I'm sorry, but I've already finished studying your kind. I have absolutely no interest in you."
(To Uryū Ishida) "Having you running around is a little inconvenient for me. Even though we have Shunpo to counter it, it's very tiring. After this I have to find that girl and study her. I'll be busy. You're not worth the effort, so I'll use the fastest and easiest way to kill you."
(To Uryū Ishida) "A man's scream is really lacking in comparison to a woman's. It's nowhere as lustful. Rather, it's unbearably annoying."
(About his Zanpakutō) "My, my. The tool defying its own master. Did it really think it would get away with that? It was designed such that if it were ever to bite at me, then it would instantly self-destruct."
(To Szayelaporro Granz) "There is nothing in this world that is truly 'perfect'. Though it may be a rather large cliche, it is still the truth. It is the ordinary people who look up to 'perfection' as an ideal and seek after it. But in truth, what is this idea of 'perfection' truly worth? Nothing. Not a single thing. I detest 'perfection'. To be 'perfect' is to be unable to improve any further. There would be no scope for 'creation', not a single gap in one's knowledge or one's ability. Do you see now? To true scientists like you and I, 'perfection' is tantamount to 'despair'. We aspire to reach greater levels of brilliance than ever before, but never, NEVER, to reach perfection. That is the paradox through which we scientists must struggle. Indeed, it is our duty to find pleasure in that struggle. In other words, the second you allowed yourself to spout a ridiculous word like 'perfect', in truth, you had already been defeated. That is, if you wish to be treated as a scientist."
(To Ichigo Kurosaki) "Oh, do be quiet. I have no need for chatter from my test subjects. This is an experiment. You are Subject #1. The rights of refusal or acceptance are out of your hands!"
(To Ichigo Kurosaki) "I see. How interesting. You are an intriguing one indeed, Ichigo Kurosaki! I had thought that it might be entertaining to close the Garganta around you, but I think I shall not! Once this battle is over, I will be sure to subject you to the very depths of terror. The kind of terror that will make you look back upon this battle as a happy and pleasant memory!"
(To Byakuya Kuchiki when asked why he is still in Hueco Mundo) "It is simple. The number of interesting corpses for me to analyse merely happens to be greater here than in the human world at this point in time. That is the only reason. Once the battle in the human world has finished, I do not doubt that the others will open a Garganta of their own accord. At that point, I will return to the Human World, locate the remains of those who have died there, and examine them one by one at my own precious pace!"
(To Giselle Gewelle) "I've restrained my dazzling splendor so that common folk like yourself might better behold my visage. No need to feel insulted, my dear. Compared to myself, all others are 'common folk'."
(In response to Giselle Gewelle summoning an army of Shinigami zombies) "Oh, dearie me. This is quite a pickle. Though they may be zombies now, these men are nevertheless members of the Gotei 13! How can a man such as myself, who may as well be the very essence of kindness made manifest and given a spinal cord and limbs, possibly bear to fight against my own former comrades-in-arms?! There is nothing for it. I will have to leave this fight to someone who has no such emotional ties."
(To Giselle) "Where is the fun in controlling someone with no will of their own, might I ask?"
(To Kenpachi Zaraki) "Oh dear, oh dear. It was for your own sake that I stabbed you, you know. There was no other choice. So please, do not stare at me with that bitter look in your eyes. Oh, my! You are still able to move your eyeballs? You really are a monstrous one. Ah, well...I suppose I will merely have to strengthen Ashisogi Jizō's paralytic qualities before the next time I stab you. But still, to think you would not only reveal the enemy's ability, but even allow me to find room for improvement in my own Ashisogi Jizō! Truly, I can feel nothing but the deepest gratitude towards you."
(To Pernida Parnkgjas) "Having sacrificed a Captain of the Gotei 13 I love so dearly - truly a tragic price to pay - we have obtained valuable information on the nature of your ability. Do you understand what this means? My strange Quincy friend. I hear no response, but I will continue. What I mean to say is this. Right now, I have made a shocking sacrifice that drives me almost to tears. And it is precisely such touching sacrifices that give rise to glorious victories. In other words... I feel you should show your respect for this wonderful sacrifice by offering yourself up to me as an experimental subject!"
(To Ikkaku Madarame regarding Pernida) "What am I so happy about, you ask? I have found a new and unprecedented subject to observe! And what is more, it continually surpasses all of my expectation! What greater cause for joy can there be?!"
"Information gained from literature is nothing more than that - information. I am not inclined to trust it without proving the facts for myself."
(To Nemu) "If you do not know, then do not act on your own judgement! You do not have my permission to die of your own accord! You will die only when I order you to do so!"
"To think the day would come when I would leave a battle to Nemu... I can scarcely stand the humiliation."
(To an apparition of Szayelaporro after it lectures him) "I cannot find any words to argue. To think that a half-baked scientist like yourself would help me to notice my own hubris. I must look quite the fool."
"Hmph. I seem to be getting thanked an awful lot today... How unsettling. But such things are not important... This is evolution! I have created from nothing a soul capable of evolving of its own accord! I have surpassed you! Kisuke Urahara! ...Ah, when I picture your face twisted in bitter envy...well, actually, I cannot imagine it... But that is precisely why it will be worth witnessing first-hand! The next time I see that man, I will make him see the difference in our abilities! Yes, we will show him... together..."
↑ 1.01.11.2Bleach Official Character Book Souls, page 158