Mayuri Kurotsuchi vs. Sawatari

 is one of the battles between the Bount and Soul Society during the Bount Invasion of Soul Society. It is the battle between the Bount, Sawatari and the 12th Division Captain, Mayuri Kurotsuchi.

Prelude
Following the Bount invasion of the Seireitei and his unintentional assistance of them being exposed by 8th Division Captain Shunsui Kyōraku at a captains meeting, 12th Division Captain Mayuri Kurotsuchi stands in his laboratory with his lieutenant, Nemu Kurotsuchi, who inquires if he will be going out in person. As he affirms this, Mayuri laments the time wasted on the captains meeting and warns the Bount that this is not over before sheathing his Zanpakutō and leaving Nemu in charge with orders to do what needs to be done.

Some time later, in a different part of the Seireitei, Sawatari senses Mabashi's actions and decides to make his move as well, but does not notice Mayuri having concealed himself with Nisehada on the archway behind him. Following Mabashi's death, Sawatari surfaces while sitting on his Doll, Baura, and acknowledges that the enemy must be skilled if they defeated Mabashi before telling Mayuri to come out, which results in Mayuri emerging from the Nisehada he had performed on the nearby wall and inquiring about how Sawatari was able to notice him even though he tried to hide his spiritual presence like the Bount do.

A chuckling Sawatari asserts that anyone could detect Mayuri's bloodthirst no matter how much he suppresses his Reiatsu, and when Mayuri asks him where Maki Ichinose is since that is who Mayuri was looking for, Sawatari admits that he does not know due to Ichinose's Reiatsu disappearing a while ago and questions if one of Mayuri's allies was responsible for this. Disappointed by this news, Mayuri decides to settle for Sawatari in order to make the Bount pay for embarrassing him. Though he does not like Mayuri underestimating him, Sawatari accepts this since he has been tasked with eliminating captains, leaving Mayuri to glare at him.

When Sawatari taps his cane against the back of Baura, the latter shifts the majority of his body out of the ground, to Mayuri's intrigue, and asks Sawatari if Mayuri is the next opponent. Confirming this, Sawatari warns Baura that Mayuri is not like the weaklings he has been fighting up until this point due to his status as a captain of the Gotei 13, which leaves Baura anticipating the fun he will have. After inquiring if this is the Doll that Sawatari uses, Mayuri chuckles, and when Baura demands to know what is so funny, Mayuri clarifies that he was just thinking that the Bount really are very interesting and wonders if Sawatari knows what the source of his power is.

With Sawatari remaining silent, a grinning Mayuri explains that his power comes from Soul Society's ancient technology, which he has no data on, and offers to let Sawatari and Baura become his test subjects, to their confusion, before detailing how he became interested enough in the Bount to want to perform his own research on them after examining various data. Though Mayuri promises to make it as painless as possible and forget that the Bount tricked him into restoring Uryū Ishida's power, Sawatari bluntly refuses due to the Bount's goal being the destruction of the Seireitei and his orders being to remove those in their way before having Baura raise his back protrusions to shield him, leaving Mayuri to exert his violet Reiatsu while vowing to make Sawatari regret this.

Battle
Despite being impressed by Mayuri's Reiatsu, Baura dives into the ground with Sawatari and asserts that it does not matter how strong his Reiatsu is while Mayuri looks down and recalls the reports he received on the ability of Baura to appear from large surfaces like the ground or walls, which he likens to a mole. As he concludes that it is useless to try this on him here compared to the Human World, Mayuri releases his Shikai, Ashisogi Jizō, and moves to the roof of the adjoining wall in order to survey the area in front of him, where he encourages Baura to attack, only for the latter to emerge from the air behind Mayuri and rush forward.

Leaping back into a pavilion to evade Baura, who crashes into the rooftop and bounces off, Mayuri is shocked to see him disappearing in midair and jumps high into the air upon seeing the ground rippling beneath his feet. With Mayuri expressing disbelief at having never heard of this ability before, Baura emerges from the ground and flies toward him, prompting Mayuri to tell Baura to not underestimate him and slash at his scales after narrowly evading the latter's maw, only for Ashisogi Jizō to be deflected without damaging Baura, who slams his tail into a stunned Mayuri, sending him crashing into a wall below and cratering it with the force of his impact.

Upon seeing Baura flying toward him once more with his mouth open, Mayuri narrowly evades him as he consumes the portion of the wall behind where Mayuri was standing, but loses his left arm in the process, leaving him bleeding heavily while Baura resurfaces in front of him. Sawatari emerges from the back of Baura and reveals that the Bount have gotten stronger by absorbing large quantities of high-quality Reishi since coming to Soul Society, meaning that the sky filled with Reishi is in the domain of Baura now in addition to the ground. As Baura claims that there is nowhere for Mayuri to run, Sawatari expresses disappointment at this being all a captain can do.

In response, Mayuri berates Baura for doing this to him and withdraws a Hojiku-Zai from his haori that he injects into the stump of his left arm, causing it to rapidly regenerate and regrow in a glow of violet Reiatsu. When an amused Sawatari comments on his interesting body, Mayuri counters that he is just an experimental subject and pulls the kusarigama out of his left ear before promising to make Sawatari shut up right now as he throws the kusarigama at him, which prompts a startled Sawatari to have Baura shield him from this with his back protrusions. With Baura lunging toward him again, Mayuri pulls back the kusarigama and leaps away, leaving Baura to crash into the area behind him, before proceeding to evade Baura multiple times with Shunpo across the pavilion.

Lamenting how he could have used Nemu as a decoy for this, Mayuri notices the craters left in the ground by the diving of Baura and deduces that though he hides himself in an alternate dimension when he is moving, Baura always shows himself and engulfs everything around him when he attacks, leading a grinning Mayuri to devise a plan and jump forward. After moving to another pavilion, Mayuri decides this should suffice and tosses several small bombs on the ground that he detonates, creating large explosions and a huge cloud of dust. Upon seeing a portion of the dust vanishing from the air, Mayuri proclaims he has found Sawatari and tosses his kusarigama forward.

With the kusarigama embedding itself in Baura, who groans in pain, Mayuri begins pulling him forward by the attached tendril and explains that Baura has to swallow everything in his way when he emerges from the alternate dimension, meaning that his movements can be sensed with enough obstacles floating in the air. As Sawatari stares in shock at this, Mayuri leaps forward and thrusts Ashisogi Jizō into Baura and Sawatari, which leads him to claim that it is over when he draws blood. Suddenly, Baura begins thrashing around and throws Mayuri into a wall, where he admits that this was pretty good while Baura falls to the ground and remains still.

Upon seeing Sawatari's bleeding right arm, Mayuri notes the wound was too shallow, and as Sawatari curses him, Mayuri states it will be easy to finish him off after coming this far, though he realizes he will have to keep Sawatari somewhat alive as an experimental subject. However, Sawatari laughs and reminds Mayuri the Bount are invincible in Soul Society because it is filled with Reishi prior to absorbing Reishi from the surrounding structures to heal his wound, which a surprised Mayuri compares to the complete control over Reishi that Uryū displayed when he used the Quincy: Letzt Stil as Sawatari asserts it does not matter how many times Mayuri wounds him.

Though Sawatari concludes that Mayuri will eventually run out of Reiryoku and be left lying face-down here, he is astonished to find that he can no longer move his right arm, prompting Mayuri to move to him with Shunpo and kick him off of Baura to the ground below, where he stomps on Sawatari's arm, causing him to scream in pain, and callously questions who will be left lying face-down. Stabbing Sawatari with Ashisogi Jizō once more, Mayuri details its power to paralyze the limbs of whoever it cuts and clarifies that it only cuts off signals from the brain to move the limbs, meaning that all pain is still felt, while twisting the blade in Sawatari's shoulder.

When Baura begins to move toward them in concern, Mayuri orders him to stay still, which Baura acknowledges, and observes that the power of Ashisogi Jizō is useful against Bount since they cannot overcome it by absorbing Reishi. With Mayuri deciding to continue looking into this discovery at the Shinigami Research and Development Institute, Sawatari calls out to Baura, and despite Mayuri claiming that it is pointless to do anything, Sawatari has Baura unleash everything he has recently consumed, engulfing a startled Mayuri in a tidal wave of dirt and debris that completely envelops and obscures the pavilion, which forces Mayuri to move to the roof.

As the dust clears in the pavilion, Mayuri sees that Sawatari and Baura have vanished, but is not concerned since the power of Ashisogi Jizō will not wear off no matter how far away he is from them and maliciously proclaims that Sawatari cannot get away. Within the alternate dimension, Sawatari sits on the back of Baura and assures the latter that his wounds will soon be healed by the large amount of Reishi that he just absorbed. Despite the wound on his shoulder healing and his ruffled suit being restored to pristine condition, Sawatari finds that his arm is still paralyzed. Refusing to disappear here and cursing Mayuri, Sawatari orders Baura to counterattack.

With Baura surfacing in the pavilion leading up to Senzaikyū, Sawatari wonders how long it will take Mayuri to arrive once he senses his Reiatsu, only for Mayuri to reveal that he is already here and cease his usage of Nisehada on the steps leading up to Senzaikyū while mocking Sawatari for being so slow. A shocked Sawatari admits that he did not think Mayuri could get here so fast, and as Mayuri praises his frightened expression as being worth letting him live instead of immediately finishing him off so Mayuri could get a good look at him, Sawatari questions how Mayuri found his location, which Mayuri decides to tell him since he is so insistent on it.

Recounting how he received a report on 10th Division Lieutenant Rangiku Matsumoto managing to track Sawatari in the Human World by using '''Bakudō #58. Kakushitsuijaku''', Mayuri asserts that he can track Sawatari even if he hides in an alternate dimension as long as he has Sawatari's Reiatsu data and elaborates that Ichigo Kurosaki chasing the Bount with a Mod-Soul that can sense their Reiatsu led him to create a sensor for the same purpose, leaving Sawatari stunned while Mayuri details how the sensor does not function without proper data and that it can only track Sawatari due to his data being input from his battles here and in the Human World.

When Sawatari realizes Mayuri has been targeting him from the beginning, Mayuri brings up the oddity of encountering him in a place as large as the Seireitei is and concludes Sawatari's Soul-aged body makes him a great experiment subject, angering Sawatari, before inviting the latter to return to his laboratory with him so Mayuri can learn more about the Bount. As he approaches Sawatari and Baura, Mayuri warns them it is pointless to run away since Sawatari's Reiatsu is completely recorded in his sensor, but a maniacally laughing Sawatari claims Mayuri is the one who is actually cornered here and has Baura unleash a '''Hadō #4. Byakurai''' from his mouth.

As an astonished Mayuri narrowly evades the blast, which slams into the wall behind him, Sawatari declares that this is the absorbed Reiatsu of the Shinigami who attacked them before now and has Baura begin firing a mixture of '''Hadō #4. Byakurai, Hadō #31. Shakkahō, and Hadō #33. Sōkatsui at Mayuri in rapid succession, forcing Mayuri to move around the pavilion with Shunpo'''. Moving out of the way when Baura hurtles toward him directly, Mayuri looks up to see Baura carving through the side of the cliff behind him, causing a torrent of dirt and debris to pour down and resulting in Mayuri jumping into the air to dodge it.

Upon seeing Baura hurtling toward him from behind, Mayuri admits that he never thought the former could move this fast, and when Baura bites down onto Mayuri's left arm, Mayuri stabs Ashisogi Jizō into his underbelly, which results in a groaning Baura crashing into the ground. In the aftermath of the crash, Mayuri stands with his entire left arm and part of the left side of his torso consumed while an agonized Baura lies next to Sawatari across from him. Noting that they are just trading blows, Sawatari winces in pain and refuses to allow Mayuri to heal himself with another Hojiku-Zai as he orders Baura to attack, though the latter struggles to move forward.

In response, Mayuri angrily admonishes Sawatari for getting so cocky despite being an experimental subject and activates his Bankai, Konjiki Ashisogi Jizō, which he explains to a stunned Sawatari will turn a deadly poison made from his blood into mist and scatter it across the surrounding area, leaving nowhere for Sawatari to escape. With a startled Sawatari picking up on his mention of poison, Konjiki Ashisogi Jizō unleashes a wave of poison mist from its mouth, which leads Sawatari to frantically order Baura to suck it in glowing with light teal Reiatsu and placing his hand on the side of Baura.

Sawatari begins channeling all of his Reiryoku into Baura, causing the eyes of Baura to flash purple as he promises to absorb all of the poison. In response, Mayuri warns Sawatari to not get cocky and abandons his plans to keep the latter as an experimental subject while his own violet Reiatsu surges alongside that of Sawatari, who refuses to die here since he violated his tribe's law by absorbing tens of thousands of Human Souls over the course of centuries in the Human World and kept doing so in order to increase his own powers and become the leader of the Bount instead of Jin Kariya, even though it resulted in his body rapidly aging to its current state.

After doubling in size from Sawatari's infusion of Reiryoku, Baura rushes into the air while continuing to absorb the poison and latches onto the face of Konjiki Ashisogi Jizō, which leads Sawatari to declare that he is the most worthy of leading the Bount and roar in anticipation. However, a smiling Mayuri wonders if this true and has Konjiki Ashisogi Jizō extend the Retractable Blades on its chest, causing them to stab into the underbelly of Baura and forcing him back from the face of Konjiki Ashisogi Jizō, who rushes forward at Mayuri's command and slams into the fallen Baura, resulting in a massive explosion of force across the surrounding area.

Aftermath
In the aftermath of this, Sawatari struggles to crawl away near the walls of one of the buildings nearby before being confronted by Mayuri, who reiterates that there is nowhere he can hide. Calling out desperately to Baura, who lies unresponsive and breathing slowly on his side several meters away, Sawatari begins frantically clutching his own throat with both hands, and as Mayuri observes that he will not be able to fulfill his goal of becoming the leader of the Bount after all, Sawatari frantically offers to give him information on the tribe in exchange for being spared, only for an unimpressed Mayuri to call him pathetic in response.

Mayuri asserts that he is no longer interested in Sawatari, who glows green and vomits dust prior to his body turning to ash and collapsing in a heap, leaving only his clothes behind. Seeing this, Mayuri deduces that the poison had already spread through Sawatari's system and laments having wasted his time here. After sheathing his Zanpakutō, Mayuri notes that he has used up all his Hojiku-Zai and walks away to return to the Shinigami Research and Development Institute. That night, 4th Division Lieutenant Isane Kotetsu informs 10th Division Captain Tōshirō Hitsugaya that Mayuri's extensive injuries are hindering his return to the battlefield.