Ōetsu Nimaiya

is a member of the Royal Guard, holding the title. He was credited for creating the Zanpakutō.

Appearance
Nimaiya is a dark-skinned man with thick, black hair that is shaven and dyed green on the sides of his head. He wears a variation of the Shinigami shihakushō, featuring instead a green undergarment, and a shortened hakama that exposes his lower legs. Worn over this is a white, sleeveless puffer jacket that bears the Royal Guard emblem on its back, as well as the alternating circle and diamond pattern of a captain's haori along the bottom. His attire is completed by gold-framed sunglasses with blue lenses, and a pair of green slippers that are gold trimmed and have a shoe-like appearance.

Personality
According to Kirio Hikifune, he is an unpredictable man. Nimaiya is quite a lively and energetic individual, being prone to grandiose entrances and greetings. He has a tendency of going overboard, as he portrays a certain image as to take away from the fact that he lives in a humble state. In battle, he retains his upbeat demeanor, even while mercilessly slaughtering his opponents, whom he casually banters with at all times. Nimaiya is not above making life-threatening decisions in order to win, such as cutting open his own throat to counter Askin Nakk Le Vaar's The Deathdealing, and is quick-thinking, having Tenjirō Kirinji replace all of the blood in his body as soon as he learned of the seemingly inescapable predicament Askin had put in him.

History
Nimaiya is credited with having created the Zanpakutō, something that even the Soul King recognized as a significant contribution to Soul Society, hence his promotion to the Royal Guard.

The Thousand-Year Blood War arc
After the death of Captain-Commander Genryūsai Shigekuni Yamamoto, he arrives in Soul Society with the other members of the Royal Guard, where they are greeted by the surviving Gotei 13 captains and Ichigo Kurosaki. He remains silent throughout the encounter and they return to the Soul King Palace with Ichigo and the injured Captain Byakuya Kuchiki, Lieutenant Renji Abarai, and Lieutenant Rukia Kuchiki.

Nimaiya is informed by Mera that Ichigo and Renji have arrived at his domain and goes to greet them. Nimaiya identifies himself to them as the number one Zanpakutō creator and brings them to a building where they are welcomed by a number of women. He formally introduces himself, forcing them to perform an elaborate formal greeting. Mera interrupts and has the group follow her to a hut on the edge of a precipice. Ichigo and Renji step inside and Nimaiya tells them that he is the only Shinigami there and that the other people are actually Zanpakutō. He notes their inability to discern the difference and states that they have no love for Zanpakutō which is why they cannot tell the difference and then shatters their Zanpakutō, saying that a Zanpakutō that is not loved breaks easily. As they notice beings around them, Nimaiya states that the wrath of the Zanpakutō is around them, and that if they can get out alive, then he will reforge their blades.

After Ichigo and Renji begin their challenge, they begin seeing creatures spurring forth from the darkness. Nimaiya tells them not to be scared as they know them well. He states that the creatures are Asauchi. Nimaiya explains that when a Shinigami joins the Gotei 13, they are given a nameless Zanpakutō which they carry around at all times, even sleeping and eating with them, which imprints the essence of their soul on the Asauchi, creating their own Zanpakutō. He then states that he forges every one of the Asauchi. Ichigo asks why they are being attacked by the Asauchi and Nimaiya says that they are angry with Ichigo and Renji because of the way they treat their Zanpakutō. He says the way they treat their swords is all wrong and that is what the Asauchi think. He then poses a challenge, the Shinigami or the Zanpakutō, which will come out on top?

After about 3 days and nights Nimaiya stops the fight between Ichigo, Renji and the Asauchi. Nimaiya congratulates Renji on his skills and tells him he passes with flying colors, while he tells Ichigo that he has failed. Ichigo asks for more time but Nimaiya tells him that it's too late, that it's over and that he is a complete failure. Ichigo pleads with him that he can keep going and he never stated there was a time limit. Nimaiya notes that while that might be true his patience does have a time limit and they have moved beyond whether or not he is capable, the fact is that the Asauchi have deemed him unworthy and therefore it's out of his hands. He further notes that if nothing else the last few days have shown him that Renji is a true Shinigami and Ichigo is in fact not one. He then assures Ichigo that the least he can do is send him home. Nimaiya then asks Mera to show Ichigo the door, he then tells Ichigo to never show his face in Soul Society as it's only a place for Shinigami and not a Human without a Zanpakutō. Ichigo asks him if he thinks he can just make him leave that easy and asks what will happen to Zangetsu if he leaves. Nimaiya tells him it doesn't really matter as either way it's not getting fixed. An enraged Ichigo lunges at Nimaiya. He restrains him and opens a portal that transports him back to Karakura Town, wishing him a pleasant trip. As the portal closes, Nimaiya notes to himself that Ichigo needs to step up his game, as the Asauchi deemed him unworthy meaning Ichigo has been able to hold his own this entire time without the Asauchi's aid. Such a thing has great ramifications and therefore it's time for Ichigo to start from the ground up; he has to crawl before he can walk, even if that means never coming back again.

Nimaiya comments to Renji that he did not protest about him sending Ichigo away. He explains that he knows why, as the creator of the Zanpakutō he knows the position of every Asauchi he has ever created, whether they are common soldiers or captains, one way or another a Shinigami needs an Asauchi in order to make a Zanpakutō. He further explains the nature of acquiring a Zanpakutō and that Ichigo having a Zanpakutō without an Asauchi confirmed he was not a Shinigami. He states to Renji that he knew the method he devised would not be passed by Ichigo and that Renji knew it as well, in fact the only one that didn't know was Ichigo himself. Nimaiya points out that Ichigo needs to find out where his soul lies.

The next day, Nimaiya sends Mera to bring Ichigo back to his palace. He tells him that Ichigo has one night to make the Asauchi accept him, otherwise the time he spent will be wasted. However, he notices that the Asauchi have already recognized Ichigo's talents. As Ichigo selects an Asauchi, Nimaiya decides to personally reforge his Zanpakutō. He then sets up a slide to lead deeper into his palace, and kicks Ichigo into it, sending him down head first with his Asauchi. He then says that he warned Ichigo about the dangers of going in head first after they reached the bottom. As Ichigo gets to his feet, Nimaiya tells Ichigo to look around at the area they have arrived at and tells him to prepare to say goodbye to his current Zanpakutō, Zangetsu.

Nimaiya summons his bodyguards to prepare the forge for him. As he begins forging Ichigo's new Zanpakutō, he states that he wants to see the flame. He then explains the reason why Ichigo was shocked when he sees the form that the Asauchi took upon contact, revealing that Ichigo's Zanpakutō is actually his inner hollow. He tells Ichigo that White was a Hollow made from a Shinigami's soul created by Sōsuke Aizen and that its composition was similar to an Asauchi. He reveals to Ichigo that he has been tricked and that the being he thought was 'Zangetsu' is not his Zanpakutō Spirit but the manifestation of his latent Quincy powers. He furthers mentions that the being's appearance is that of Yhwach as he appeared 1000 years ago.

As Nimaiya finalizes the forging, Ichigo, having spoken with the Quincy side of Zangetsu, chooses to keep it, grabbing the heated blade. While surprised by this, Nimaiya realizes Ichigo pouring his own soul into the forging would be better. As Ichigo lifts the blade, a huge eruption occurs, vaporizing the entire sea around them to cool off the Zanpakutō. Watching in acknowledgment as Ichigo holds his now-twin blades of Zangetsu, Nimaiya asks him how they feel. The next day, when Yhwach, Jugram Haschwalth, and Uryū Ishida arrive at the palace, Nimaiya senses their presence. Later, after Hikifune traps the invaders in her cage of life, Nimaiya confronts them, draws his Zanpakutō, and proclaims that the real battle begins here.

When Gerard Valkyrie attacks him, Nimaiya dodges by leaning back and informs a pleased Gerard that it is only natural to dodge such attacks. Gerard attempts to attack him again, but Nimaiya cuts him down with a single swing, shocking the other three Sternritter. Lille Barro fires several Heilig Pfeil at Nimaiya, who merely deflects them with his Zanpakutō before explaining how it is easy to do so and cutting Lille down with a single slash of his sword. Impaling Pernida Parnkgjas through the head with his sword, Nimaiya pulls it out and cuts down Askin Nakk Le Vaar, whom he compliments on his attempt to catch Nimaiya off-guard. Nimaiya slashes Askin's throat and explains how his Zanpakutō is too strong to wield against normal combatants before claiming that Yhwach is gonna allow him to rock the world with it, only to be surprised when Askin, having survived with The Deathdealing, tells him it is not over yet.

Askin explains how The Deathdealing lets him control the lethal dosage of substances as Nimaiya collapses. When Askin reveals he has made the blood in Nimaiya's body lethal to him, Nimaiya cuts his own throat to let the blood out, prompting Askin to point out how doing so will eventually kill Nimaiya due to blood loss. Noting this, Nimaiya has Kirinji replace his blood with his hot spring water before cutting Askin down. As Askin falls, Nimaiya turns to Yhwach and challenges him. Nimaiya notes that the Royal Guard have very little information on Yhwach's abilities before deciding that he must cut off Yhwach's arms and go from there. Soon afterward, Nimaiya is shocked when Yhwach uses Auswählen to revive his elite Sternritter.

When his shoulder is shot twice by the revived Lille, Nimaiya wonders what just happened, prompting Haschwalth to explain how Auswählen redistributes power between Quincy to revive Yhwach's chosen. Nimaiya theorizes that this boost in power is why Lille's bullets can penetrate his body now, but Lille reveals that this is merely a power that he had not had the opportunity to fully unleash before and that he is not firing bullets before firing at Nimaiya again. Kirinji and Hikifune seemingly block the shot, but are shocked to see Nimaiya has been shot through the heart.

Inventions

 * Zanpakutō: Nimaiya is the man responsible for creating the Asauchi, the base templates for what will eventually become a Shinigami's unique Zanpakutō.

Equipment

 * An incredibly sharp sword forged by Nimaiya, its forte is somewhat unstable due to Nimaiya not having drawn it in a long period of time. Nimaiya considers Sayabuse a failed creation because its blade is too sharp and its edge is too smooth; it never chips or scratches from use, and blood slides off it immediately. Because of this, no sheath can hold it, which means it fails to meet the basic definition of a sword.


 * Sword Tank: Nimaiya keeps Sayabuse stored in a large tank of jelly-like liquid.

Powers & Abilities
Master Swordsmith: Nimaiya is the creator of the Zanpakutō and therefore the foremost authority on its history, construction, and capabilities. He has the greatest understanding of the Zanpakutō, and is the only individual capable of reforging a broken Zanpakutō. He forges the strongest Zanpakutō, the Asauchi, as they can become anything.

Zanpakutō Sense: He knows the exact position of all the Zanpakutō that he has ever created, no matter how the wielder attained it or who the wielder is.

Master Swordsman: Nimaiya is a master of sword technique, skilled in evasion, offense, defense, and counterattacks. He can dodge swift and direct melee attacks with little to no effort. He can take down his opponent with a single extremely fast strike that cannot be detected or registered until it has already taken place, and he can effortlessly deflect enhanced Heilig Pfeil. He is also extremely agile and possesses incredible reflexes.

Shunpo Expert: Nimaiya is an extremely fast combatant, quickly overwhelming four Sternritter with rapid attacks and movements before most of them could react properly.

Kidō Practitioner: Nimaiya is skilled enough with Kidō to fire a blast from both of his hands simultaneously without an incantation.

Enhanced Endurance: Nimaiya is a considerably resilient combatant. While facing off against Askin Nakk Le Vaar, he cut his own throat to reduce the amount of blood in his body and managed to move behind Askin for a surprise attack while constantly losing blood; Askin noted that Nimaiya should have been unable to stand at that point.

Immense Spiritual Power: As a captain-class combatant and current member of the Royal Guard, Nimaiya has an immense amount of spiritual power, which he demonstrated when he effortlessly defeated three of Yhwach's elite Sternritter in rapid succession with a single attack each.

Ōken: As one of the Royal Guards, Nimaiya has the Ōken imparted in his bones, which grants him the ability to travel into and out of the Soul King Palace, as well as grant permission to others simply by willing it.

Zanpakutō

 * Shikai: Not Yet Revealed
 * Bankai: Not Yet Revealed

Trivia

 * Nimaiya's name is sometimes romanized as Oh-Etsu Nimaiya.

Quotes

 * (To Ichigo Kurosaki and Renji Abarai regarding Zanpakutō) "Don't get it? Can't blame ya. How you fight? How you attack? No, no, no. What's wrong? It's all wrong! You've used your Zanpakutō as tools? Treated them like subordinates? Relied on them like partners? As family? As friends? Role models? Students? Pets? Acquaintances? Sweethearts? Lovers? Don't make me sick!!! That's what these guys are tryin' to tell you. You're looking at things completely the wrong way. Which is superior, the Zanpakutō or the Shinigami? Let's think about that to start with, yeah?!!"


 * (To Yhwach's elite Sternritter) "You be lookin' at the No. 1 Zanpakutō creator! Not Jū, not Kyū, not Hachi, not Nana, not Roku, not Go-mai! Not Shi or San-mai! The name's Nimaiya Ōetsu! And I ain't lettin' no trash get past me here. So shut up, buckle down, and give it your best shot. 'Cause you're about to taste a real Division Zero battle."


 * (To Gerard Valkyrie) "Hugs from men are made to be dodged."


 * (To Yhwach) "This blade, "Sayabuse", is one of my failures. Its blade is too sharp, and its edge too smooth. No matter how much you use it, it'll never chip or scratch, and not a single drop of blood will stick to it. Hell, this thing would put professional blade sharpeners out of a job. But the worst part is, I can't make a scabbard that'll hold it. Without a scabbard, it hardly qualifies as a proper sword, so I couldn't send it down to Seireitei. That's why I'm pretty happy you've come all the way up here to the Spirit Palace! Thanks to you, I got my chance to use this little fella. I really appreciate it, Y.H.!"


 * (To Askin Nakk Le Vaar) "When you say you're lowering the lethal dose of my blood, that means if I have lots of blood in my body, I'll die, yeah? Then if I just let tons of that blood out 'til it's below the lethal dose, I'll be all good, right?"