Overhaul looks like a typical man in his 20s, with short, brownish hair and eyes that are often bloodshot.
He wears a green coat with a furry collar as well as a pair of disposable medical gloves. His most distinctive feature is an orange, beak-shaped mask reminiscent of a plague doctor.
When he uses his Quirk, he appears to get rashes through his entire body.
While being transported to the Villain Hospital in Tokodana, Tomura cuts off one of Chisaki's arms and Mr. Compression takes the other.
After fusing with Shin Nemoto, Kai gets an additional two arms deformed with spiked claws and black parts of Shin's cape. His hair gets spikier, and his mask rips apart. It seems to be fused onto his face which is also covered in black fabric. Shin is presumably conscious in the fused form as his mouth is used through Chisaki's right hand and his Quirk is able to be in use.
After fusing with Rikiya Katsukame, Kai's lower body is fused into a monstrous stone structure, protruding multiple appendages each equipped with clawed hands. Kai's upper body is the same but lies within the mouth of the structure. The upper jaw has Rikiya's mask.
Overhaul appears to be insane, believing that everybody around him is sick. He seems to see the world of Quirks and Heroes as a world filled with disease that he calls 'Hero Syndrome'. He appears to despise any acts of kindness and altruistic behavior, as he sees it as some sort of illness that had been brought about due to the Heroes in society. He also seems to outright hate Quirks, wanting to use Quirk Destroying bullets as a way to bring people down by destroying their Quirks. He seems to suffer from mysophobia, showing worry when around unclean places. Overhaul despises being touched by other people.
As a leader of his organization, Overhaul is levelheaded and possesses a strategic mindset. According to a conversation with Twice, Overhaul seems to be nice at first. Whether he is acting or behaving genuinely, Overhaul does possess polite mannerisms when he is not agitated and thinking straight. This is evident from his meeting with Mirio and Izuku. He will speak to others in a very composed manner, and display very good social skills in the required situation. However when he's aggravated, Overhaul will become extremely violent and does not discriminate if his victims are villains or not. When he is touched, he will display a very sinister and dark side to his personality, before lashing out with his Quirk. He is willing to use his own subordinates as human shields.
Overhaul apparently has plans to become the next ruler of the underworld, going directly against Shigaraki but is also willing to use Shigaraki's influence as a way to further his own plans. He also appears to care little if not none for his expendables in dire situations, destroying Shin Nemoto and himself to fuse and restore his stamina. Chisaki as stated by Kurono is a man who will do anything to reach his goals.
Despite his strong willed attitude, he is capable of expressing true fear and shock as he was horrified when the League of Villains took both his arms and taunted him for his lack of power. His facial expression was that of horror as he was taunted for now being the very thing he wanted on others.
Overhaul was found and up brought by the boss of Shie Hassaikai. He was put in charge of watching over Eri and performed experiments on her to determine the true nature of her Quirk, calling it cursed. Overhaul is a yakuza, being part of an organization that, along with several others, ruled the underworld in the past. With the rise and prominence of heroes, in particular All Might, those organizations started crumbling down and the remnants who were not arrested were forced to live under constant surveillance. Overhaul, thus, is described as part of a "dying species".
Overhaul and some of his subordinates are first seen destroying the getaway vehicle of Team Reservoir Dogs. He comments on how weird it is that a group of adults teamed up just to steal a cash register from a store, and declares that they were sick.
Overhaul enters the League of Villains' hideout but is unimpressed with Tomura and his members as well as his unclean hideout. Overhaul explains to the League of Villains that with All For One's downfall, someone will eventually become the next ruler of the underworld. However, Tomura replies that he will become the next underworld ruler after he gather more members and crush the current Hero society. Overhaul asks Tomura if he has a plan, to which Tomura responds that he thought Overhaul wanted to join them. Overhaul is disappointed that Tomura does not have a plan to achieve his objective and laments that he wasted the potential of Stain, Muscular, and Moonfish. Overhaul reveals that he wants the League of Villains to join him so that he can teach them the proper way to run an organization and use them to gain financial capital so that he can get one step closer to becoming the next underworld ruler.
However, Magne rejects this proposal and magnetizes Overhaul, bringing him into Magne's range. Magne hits Overhaul on the head with her weapon, to which Overhaul responds by touching Magne. Overhaul's physical contact causes Magne to blow up, much to the League of Villains' shock. Overhaul blames the League for throwing the first punch and dislikes the blood running down his face. Mr. Compress charges forward and touches Overhaul but his quirk does not activate due to being shot in the arm. Overhaul is enraged that he has been touched and severs Mr. Compress's left arm by blowing it up. Furious, Tomura dashes to Overhaul and prepares to decay him. Overhaul calls for a human shield. Tomura touches Overhaul's subordinate instead which causes Tomura to disintegrate the subordinate.
Suddenly, Overhaul's subordinates crash in. Seeing that both of their organizations have suffered casualties with the deaths of their respective members, Overhaul ceases fighting and will talk to Tomura again after he calms down. Himiko Toga and Twice want to kill Overhaul for murdering Magne, but an equally angry Tomura stops them. As he walks out, Overhaul throws a business card at Tomura's feet and tells Tomura to call him again after he has calmed down and thought about the organization he wants to build.
The following weekend, Overhaul chases after Eri and unintentionally bumps into Izuku Midoriya and Mirio Togata. Chisaki apologizes to Izuku for his daughter's behavior because she gets carried away with her fun and games. Mirio tells Izuku that he forgot to put his mask on. As Mirio apologizes to Chisaki, Izuku is aggravated by his mistake of letting Chisaki know that he and Mirio know each other, which will make Sir Nighteye's job more difficult. Izuku acts innocuously to correct his mistake while Mirio identifies Chisaki as a member of the Eight Precepts of Death due to his mask, to which Chisaki states not to pay heed to his mask as he simply dislikes dirt. Chisaki mentions that he has never seen the two of them before and wonders if they are rookies due to their youth. Mirio replies that they are indeed rookies. Chisaki asks Mirio the Hero office he is affiliated with and Mirio replies that they are still students participating in field training. Mirio and Izuku prepare to leave, but Eri tells Izuku not to leave as she starts shedding tears.
Izuku tells Chisaki that his daughter is frightened by something, to which Chisaki replies that he scolded her. However, Izuku is not convinced since Eri is clutching onto him tightly and suspects that there is more than meets the eye. Izuku asks about the bandages, which Overhaul replies that Eri falls down a lot, but Izuku is still not convinced as she is completely frightened and finds the situation to be unnatural. Chisaki politely asks Izuku to not impose his idea of normal on other's families while Mirio tries convincing Izuku to leave since many people have different dispositions. Izuku breaks the ice and asks Overhaul what he is doing to the girl.
Chisaki gives in and tells the Heroes to follow him as his situation with his daughter is an embarrassing topic. Chisaki, Mirio, and Izuku holding Eri follow Chisaki into the alley. Chisaki comments that his daughter defies him all the time and finds understanding children to be quite difficult especially when it comes to considering the kind of person they want to become. Izuku and Mirio see Chisaki removing his glove and has killer intent. Suddenly, Eri runs to her father, causing Chisaki to stop removing his glove. Chisaki apologizes to Izuku and Mirio for Eri's tantrum and thanks them for listening to his worries. Chisaki wishes the Heroes good luck as he leaves with Eri. Mirio stops Izuku from going after Eri while commenting that Chisaki used his killer intent to make Eri listen to him. Mirio asks Izuku to respects Sir Nighteye's orders because chasing Chisaki too far will make him harder to catch.
At his hideout, Chisaki comments on Eri's sickly behavior and asks Chrono to prepare a bath as his subordinate apologizes for letting Eri out of his sight. However, Chisaki is not interested in the subordinate's excuse and kills the subordinate with his Quirk, telling Chrono to clean up as well. Chrono prepares to carry out his leader's orders while Chisaki comments that all people are sick with Hero Syndrome. Chisaki wants Eri to stop being selfish as she is the key to his entire plan. Chisaki shows her an experimentation lab and asks her to no longer sully his hands.
A few days later, both Chisaki and Tomura Shigaraki meet face to face once again, this time in a room beneath the Eight Precepts of Death's headquarters.
Mimic asks Tomura if what he said on the phone the other day was true; that he would side with them depending on the conditions. Tomura puts his foot on the table and states that their villain organizations' motives align; Chisaki wants to use the influence of the League of Villains' name while he wants to expand their influence. Chisaki asks Tomura to put his foot off the table, but Tomura defiantly says that he should be bowing before him in respect. Tomura tells Chisaki that the League of Villains do not answer to anyone and they move however they like, but that the League of Villains are willing to work with anyone in a "joint venture". Chisaki asks if this is the only condition, to which Tomura states there is another condition: Chisaki must tell him about his plan since he cannot give his organization's name for a worthless scheme. Tomura reaches into his coat for something. Suddenly, Chronostasis, Chisaki's right-hand man, puts his gun at Tomura's head while Mimic uses his Quirk and grabs Tomura on the head. Chisaki orders Chronostasis and Mimic to leave Tomura alone as he willingly came to their hideout to discuss the future. Chronostasis and Mimic obey their leader's command.
Tomura pulls out what seems to be a tranquilizing bullet and says that Atsuhiro was no longer able to use his Quirk after the bullet was fired onto him, he then asks if Chisaki's plan has something to do with it. Chisaki replies that he is going to destroy justice. Chisaki comments that he heard that All For One controlled others by taking their Quirks; his plan brushes up on that approach a little bit and notes that all the preparations are proceeding according to plan.
A few days later, after a meeting regarding the Eight Precepts of Death, the heroes have decided to raid theirs headquarters in order to save Eri. Inside his headquarters, Chisaki notes that the heroes have come. Two minutes after Mirio went off on his own, Mirio manages to find Chisaki and Chronostasis. Mirio asks if he can talk with Chisaki a bit more. Chisaki recognizes Mirio.
Mirio Togata is able to catch up with Chronostasis and Chisaki. Chisaki is surprised that Mirio was able to get to them so easily; Mirio replies that he took a shortcut and is here to take Eri into custody. However, Chisaki is adamant that Eri doesn't want to be in Mirio's custody and mocks Mirio for his futile heroics, to which Mirio replies that he came to rectify his mistake. Seeing that there is no point in persuading Mirio, Chisaki begins to walk away along with Chronostasis. Mirio charges towards Chisaki as the Eight Precepts of Death's leader tells Mirio to die. Suddenly, Mirio's sense of balance becomes hazy and he falls onto the ground. Mirio's unbalance is due to Deidoro Sasaki, a member of the Eight Expendables. Mirio realizes that Deidoro's Quirk is making him unbalanced as another of the Eight Expendables, Shin Nemuto, fires his gun at Mirio. However, Shin's bullets phase through Mirio. Shin asks Mirio about his Quirk, to which Mirio reveals his Quirk's ability. However, Mirio did not actually want to reveal his Quirk to the enemy which surprises him.
Deidoro criticizes Shin for missing, causing Shin to knock Deidoro's beer bottle away from him in retaliation, reminding him to support him. Mirio realizes that Shin's Quirk lets him force people to talk. Shin fires at Mirio again as Mirio's body phases the bullets; Shin comments that he is different from the other Eight Expendables as only he is privy to Chisaki's ambitions, although Mirio rhetorically questions Chisaki's abuse of his daughter. Shin replies that compassion is unneeded for progress to smoothly flow and Mirio should understand as well, referring to him overlooking the incident when he first encountered Eri, to which Mirio says that he is correct, which shocks Mirio as he didn't want to say that. Shin Nemuto's Quirk, Spitting the Truth, forces his opponent to answer his questions with their true feelings. Before he was scouted by the Eight Precepts of Death, Shin was a con man with repeated offenses. Shin knows all too well that people hide their true natures which are their weaknesses and at times, he will draw out their weaknesses that even his victims were unaware of.
Shin questions Mirio's motives for saving Eri, wondering if he only wants to save her to make himself feel better. Mirio has stopped in his tracks. Seeing that Chisaki is leaving, Shin decides to finish off Mirio so that he can quickly rejoin Chisaki. Shin fires his bullets and Deidoro throws his knives at Mirio. Suddenly, Mirio uses Phantom Menace, a move in which he phases himself and quickly strikes down his opponents, knocking down both Shin and Deidoro. Mirio agrees with Shin that he let Eri go back into despair and already knew that he carried a sin for doing so. Mirio is a man who grew to accept his weaknesses and was able to strive to achieve his goals because he acknowledged his weaknesses; the same holds true about his heart in that his weaknesses were not something to hide. Deidoro is surprised that Mirio could move well under the effects of his Quirk, although Mirio is able to withstand Deidoro's Quirk effect thanks to putting up with many sensations on a daily basis. Mirio cannot stand to see Eri without a smile on her face and finds that to be unforgivable. Mirio quickly strikes Deidoro and Shin again and charges towards Chisaki.
Mirio appears before Chisaki and attacks simultaneously. Mirio strikes Chisaki with a backhanded smack, to which Chisaki avoids, but he still managed to leave a mark on Chisaki's face while kicking Chronostasis. Mirio avoids hitting Eri thanks to his Permeation and strikes Chronostasis down with his kick. Chronostasis falls back as Mirio grabs hold of Eri. Eri tells Mirio to run away otherwise Chisaki will kill him. However, Mirio promises to never let Eri be sad again and tells her that everything is fine because he is her Hero.
Mirio Togata has recovered Eri from Kai Chisaki. Chisaki begins wiping off the mark Mirio left on his face as he threatens Eri to return to him because she was born to destroy people, otherwise Mirio will be murdered. Before Eri can speak, Mirio tells her to not listen to Chisaki's words. Chisaki becomes annoyed that Eri's selfishness has caused him the need to get his hands dirty. Chisaki mocks Eri for her existence being a curse, much to Mirio's chagrin who wonders why Chisaki is saying such harsh words to his own daughter. However, as he takes off his glove, Chisaki reveals that Eri is not his daughter. Chisaki places his hand on the ground and deconstructs it using his Quirk.
Chisaki reconstructs the crumbled ground into massive spikes that attack Mirio, but Mirio phases his body while holding up Eri with his arms, protecting both of them. Mirio is surprised at Chisaki's quick speed as well as his lack of regard for Eri while Chisaki himself praises Mirio for being more than just his Quirk. Chisaki launches more spikes at Mirio, uncaring at Eri's safety since he can just "repair" her easily and reveals to Mirio that Eri has experienced it firsthand; Chisaki's words enrage Mirio. Mirio continues avoiding the spikes while Chisaki asks Mirio about Eri's safety in his hands since if she gets hurt she cannot be healed immediately and that having her is making it troublesome for him as he cannot run away using his Permeation while carrying Eri. Due to him reconstructing the area with spikes, Chisaki has managed to cut off Mirio's escape route. Chronostasis has awakened and has a gun in his hand that is loaded with Quirk-disabling bullets. Mirio is surprised that Chronostasis is still awake after being hit by him and assumes that Deidoro Sakaki's Quirk made his physical attacks weaker at the time. Chisaki orders Chronostasis to aim at Mirio's arms while he destroys the spikes so that Mirio loses his ground. Chisaki deconstructs the ground, causing Mirio to be in mid-air. Mirio conceals himself and Eri using his cape; Chronostasis fires at Mirio but misses due to his target being concealed by the cape.
Suddenly, Chisaki realizes that Mirio will appear before Chronostasis and begins reconstructing the ground beneath his second in command. Mirio does indeed appear before Chronostasis, using his Quirk's instant transportation to do so. Mirio's shoulder knocks Chronostasis's arm which causes him to drop the gun and is about to hit Chronostasis with a punch, but Chisaki launches Chronostasis away from Mirio by reconstructing a platform which saves Chronostasis, who apologizes to Chisaki. Seeing that Mirio is stronger than he thought, Chisaki decides to break Mirio's morale by killing Eri. Before he can do so, Mirio uses his instant transportation to appear behind Chisaki. Chisaki realizes this and tries blocking Mirio with his hand, but Mirio phases his arm through Chisaki and punches him in the face.
Chisaki lands on the ground as Mirio states that his cape is for bundling up Eri who is in terrible pain. Chronostasis gets up and tries getting the gun, only for Mirio to appear before him and knock him back down. Mirio praises Chisaki for his abilities being far above that of the average yakuza but tells him that he is far stronger, using his instant teleportation to appear before Chisaki and lands another punch against him. Eri watches the fight and is surprised at not only Mirio's strength but the lengths he is willing to go for her. Mirio swears to never let Chisaki lay another finger in Eri and promises to take them both down, declaring that he has them in checkmate.
Chisaki becomes enraged at Mirio calling out his name since he abandoned it long ago. Years ago during Chisaki's childhood, the boss of the Eight Precepts of Death took Chisaki in since he had nowhere he could call home and asked for Chisaki's name, to which he states that his full name is Kai Chisaki. Several years later, the boss of the Eight Precepts of Death lamented about the destruction of a yakuza group; Chisaki told the boss about the plan he had discussed with him before, but the boss did not take heed of it because falling off from the part of humanity would cause his demise as a gangster since people would not follow brutes with no hearts.
Without a doubt, Mirio Togata had defeated Shin Nemoto by overwhelming him with three strikes to the head as well as removing the bullets from his gun. For ten minutes Shin's mind was clouded and he could not move. However, Shin is able to maintain consciousness and continue crawling because of his undying devotion to Chisaki. In the past, whenever Shin questioned someone about their true nature, they would always lie to him and whenever he asked why they lied, they became flustered and distanced themselves from him which made it difficult for Shin to makes friends as all he wanted was one friend he could trust. That one friend Shin wanted trust from was none other than Chisaki.
Because of Chisaki being the only person to be honest with him, Shin became utterly devoted to Chisaki. Shin continues crawling towards Chisaki with tears rolling down his right eye. Chisaki sees Shin as well as Mirio. Chisaki immediately throws a case of Quirk-disabling bullets at him. Shin opens the case and loads one of the bullets in his gun. Chisaki orders Shin to open fire as Shin aims his gun at Mirio.
As he throws the Quirk-destroying bullets to Shin, Chisaki thinks about the lengths his organization had to go through in order to create the lethal weapon; originally, the effect of the element emitted from Eri's body would only cause a victim to lose their Quirk for a day or two and they would naturally recover. In order to obtain a complete product, they needed to figure out how to permanently preserve the element's effect which they eventually succeeded. However, due to money and time constraints, Chisaki could only make five Quirk destroying bullets. The reason Chisaki took action in making these Quirk destroying bullets is because of All For One's downfall.
Shin grabs the case of Quirk destroying bullets and Chisaki orders him to fire. Only Shin knows the value of the Quirk destroying bullets and cannot waste a single shot; Shin tries to figure out a way to make Mirio deactivate his Quirk. Suddenly, Shin realizes that Mirio will do whatever it takes to protect Eri, so he aims his gun at Eri. Mirio immediately jumps towards Eri. Mirio was able to tell that Eri was endangered because she wouldn't scream or cry whenever murderous intent was directed at her and she would simply close her eyes, be silent and grit her teeth; this was Eri's habit that was engraved in her after living in pain and fear for a long time.
Mirio has reached Eri while Shin fires the Quirk destroying bullet. Eri opens her eyes and sees a smiling Mirio who is about to be hit by the Quirk destroying bullet. Mirio thinks about his childhood where his family's Quirk made it difficult for them to become Heroes, which is why his father gave up on becoming a Hero. However, Mirio refused to waver and throughout his life he worked extremely hard to hone his Permeation; eventually, Sir Nighteye saw potential within Mirio and made him his sidekick. Under Sir Nighteye's guidance, Mirio was able to turn his Permeation into a fully combat Quirk; during this time Mirio along with Tamaki and Nejire began being acknowledged as the Big Three.
Mirio covers Eri as the Quirk destroying bullet is shot into his body which begins destroying Mirio's Permeation. Chisaki states that due to Quirks people are entitled to dream and begin thinking that they become people that matter, to which Chisaki believes that these people are sick in the head. As Shin celebrates his triumph, Chisaki laughs at Mirio's efforts and mocks Mirio for smiling because everything he has worked so hard to cultivate has been reduced to naught. As Chisaki is about to deconstruct the ground, Chronostasis is thrown at him, courtesy of Mirio's kick. Mirio appears before Chisaki and punches his arm. Mirio tells Chisaki that all his hard work isn't in vain because he will still be Lemillion. Chisaki tries attacking Mirio but Mirio is still able to make his body intangible, which causes Chisaki to miss. Shin is shocked that Mirio's Quirk hasn't completely been destroyed yet.
Fifteen minutes have passed since Mirio caught up to Chisaki and now, 5 minutes have passed since Mirio was shot by the Quirk destroying bullet and he continues fighting Chisaki. Eventually, Mirio loses his ability to use his Permeation. Mirio fights one-third of the battle in a Quirkless condition which allows Chisaki to finally damage Mirio. Mirio is hurt and damaged by the spikes Chisaki created. Despite being greatly damaged himself, Chisaki mocks Mirio for wanting to be a Hero and to try and save Eri; Chisaki blames that delusional thinking for being the problem with today's society and will cure everyone using Eri's power. Chisaki is about to pierce a spike through Mirio, but Mirio yells out Chisaki's name, much to Chisaki's chagrin. Suddenly, Izuku comes smashing in. Izuku sees Chisaki and delivers a One For All: Full Cowl punch to his arm. Izuku's enhanced punch sends Chisaki flying back; Shota tells Sir Nighteye to secure Eri. Sir Nighteye is amazed that Mirio Togata has been fighting all by himself against the boss of the Eight Precepts of Death and his closest aides by himself and not only managed to defeat the aides as well as injuring Chisaki but on top of all that, managed to rescue Eri. Sir Nighteye grabs hold of Mirio and Eri. A proud Sir Nighteye praises and congratulates Mirio for everything that he has done.
Izuku and Shota charge at the injured Chisaki; Chisaki tries using his Quirk but to no avail as Shota has disabled it with his Quirk. Cornered with nowhere to run, a distressed Chisaki orders Chronostasis to wake up. Shota notices something approaching them and pushes Izuku aside; Shota's shoulder is struck by a minute hand that is emanating from Chronostasis's head. Chronostasis reveals that his Quirk allows him to manifest a minute hand and anyone struck by it will have their movements slowed. Chisaki is glad that Chronostasis has woken up; he was able to heal Chronostasis when Mirio kicked Chronostasis towards him and during that moment he fixed his head. Shota is forced to blink due to the cut from Chronostasis, which allows Chisaki to use his Quirk again. Chisaki belittles the Heroes' efforts as he constructs massive spikes from the ground, which stalls Izuku and Shota.
Chisaki refuses to allow his plans to be ruined by the Heroes. Chisaki knows that Shin Nemoto also wants him to succeed and approaches him. Chisaki thanks Shin for everything he has done for him and knows fully well that he will gladly die for his sake. Chisaki uses his Quirk and destroys both himself and Shin. Chisaki and Shin's deconstructed bodies reconstruct and fuse together with Chisaki, much to Izuku's horror.
Chisaki admits that Mirio was stronger than him but his efforts will all be in vain. The fused and transformed Chisaki appears, looking monstrous and grotesque with sharp bird-like arms from his shoulder blades and his original arms becoming larger with sharp claws. The transformed Chisaki declares that Eri will be returning to him.
Having fused with Shin, Chisaki feels relieved. Izuku analyzes the situation; Sir Nighteye is protecting Mirio and Eri, Shota has disappeared and the transformed Chisaki has been healed. Chisaki mocks Mirio for wasting his time trying to become a Hero as it has been all for naught now that he has lost his Quirk and could have avoided this tragic fate had he simply not got involved. Izuku and Sir Nighteye are surprised that Mirio has lost his Quirk. Chisaki continues bashing Mirio for continuing his Heroics even after losing his Quirk as it has now dragged his peers into his mess.
Chisaki charges forward while Izuku appears above and throws a column of rock at Chisaki who destroys it with ease. Izuku grabs another column of rock and tries again only for Chisaki to smash it to pieces and counters by reconstructing the broken pieces into sharp stones. However, Izuku's iron soles protect him from the sharp edges and he proceeds to smash Chisaki's constructed sharp stones into pieces. Seeing Izuku's simple battle style, Chisaki is not impressed. Suddenly, Chisaki is hit by one of Sir Nighteye's Hypermass Seals but manages to block it; Sir Nighteye orders Izuku to protect Mirio and Eri while he handles Chisaki. Izuku goes to Mirio and Eri's location with his enhanced speed as he remembers Shota telling him to not do anything that will leave him unable to move.
Sir Nighteye asks about Shota's whereabouts, to which Chisaki reveals that he took an interest in Shota's Erasure Quirk and his subordinates are escorting him to the meeting room, causing Sir Nighteye to wonder if Chisaki is afraid of having his own Quirk destroyed. Sir Nighteye assumes that Chisaki has completed his Quirk Destroying bullets and used one on Mirio. Sir Nighteye mocks Chisaki for being afraid of Mirio's power as Chisaki creates more arms for himself to attack with using his Quirk. Chisaki attacks but Sir Nighteye is able to evade his attacks. Chisaki sees that Sir Nighteye's movements are familiar and assumes that he is Mirio's teacher. Sir Nighteye thinks back to the lessons he taught Mirio and is happy as well as proud that he took his teachings to heart. In return, Sir Nighteye vows to keep him and the person whom he wants to protect out of harms way.
Izuku reaches Mirio and Eri and sees that they are fine. Izuku smashes open the wall which reveals the path he along with Shota and Sir Nighteye took to get here. Izuku decides that they should put distance between themselves and Chisaki. Izuku carries Mirio and Eri into the pathway; Eri apologizes while Mirio looks back to see Sir Nighteye.
During the battle between him and Chisaki, Sir Nighteye activated his Foresight Quirk. Whatever future he sees cannot be changed; this is the absolute rule as he himself has tried to change the future to no avail. Ever since he saw All Might's death, Sir Nighteye decided to never read people's futures and would only looks seconds and minutes into the future from then on. Sir Nighteye did everything in his power during the battle to deny Chisaki the future that was in his grasp and even though his actions were drawing out the inevitable this was the best course of action he could take. Unfortunately, Sir Nighteye reached his limit and was impaled by Chisaki's reconstructed rock spikes. Having touched Chisaki, Sir Nighteye saw into his future; amidst the scene of his likely defeat, Sir Nighteye held onto a silver of hope that Eri would be saved, the boys safe and Chisaki defeated as well as imprisoned.
Chisaki goes past the impaled Sir Nighteye and chases after Izuku. Izuku is horrified at Sir Nighteye's terrible condition as Chisaki launches rock spikes at Izuku. Izuku stomps on the ground using his enhanced might, preventing Chisaki from reconstructing the ground. Chisaki sees through Izuku's plan but is surprised that Izuku is displaying greater strength than a few minutes ago. The reason for Izuku's enhanced might is because he has activated One For All 20%, even though its making him feel great pain.
Chisaki berates Izuku for joining the fight and that he will end up dying. However, Izuku refuses to let anyone die even if that's what fate decided. Using One For All 20%, Izuku charges at Chisaki while declaring that he will bend the future.
Izuku's attack defeated Chisaki who fell to the ground defeated and unconscious.
He was subsequently arrested and was to be transported to a villain's hospital but the police escort was attacked by League of Villains. Despite the intervention of a hero, the efforts of the villains prevailed and they proceeded to retrieve Chisaki. He was unfazed by their arrival but he got surprised when Mr. Compress compressed part of his arm. He got angry when Tomura stole his quirk drug however, his rage turned to fear as Tomura decayed and cut off other arm. Tomura then sadistically taunted the now helpless and powerless Chisaki, at how he wanted others to lose their Quirks but now he himself is one of them. Chisaki was left screaming in frustration at this turn of events, as he watched Tomura make off with his creation.
A news report later detailed the attack on the police escort but no information was given on Chisaki's status.
Quirk and Abilities
Overhaul: Chisaki's Quirk allows him to disassemble and reassemble objects through physical contact. When he touched Magne, the entire upper half of her body was obliterated, reducing it to nothing but blood. He seems to be able to control the level of destruction this causes to a certain degree, as when he used it on Mr. Compress, he only destroyed his arm, whereas Magne was utterly eradicated. He regularly wears gloves to curb his power's effects, hinting this could also mean Chisaki has no control over the activation of his Quirk. Sir Nighteye assumes that Chisaki's Quirk is responsible for the healing of the Team Reservoir Dogs. After feeling intense pain and losing consciousness, they mysteriously came out unscathed and have their chronic illnesses cured. Another attribute of Chisaki's Quirk lies in his ability to reformat the physical shape of whatever his power is affecting, shattering and rearranging the floor beneath his feet into crushing spikes, walls or branching thorns at will.
Overall Abilities: Chisaki is very powerful, as he was able to defeat Rappa, who is also powerful in his own right to the point where he overwhelmed a Pro Hero and a U.A student with little effort, five times with no effort. Chisaki was able to hold his own against U.A's strongest student, Mirio Togata, for a long period of time.
Enhanced Agility: Challenged five times by Rappa and each time Rappa lost despite his speed and strength, implying that Chisaki has high speed and reaction time of his own to be able to accomplish this as his Quirk requires him to touch his opponent for it to take effect. Chisaki's fast reaction time is shown when he was able to evade Mirio Togata's punch, albeit he was left with a scratch on his face.
Enhanced Durability: Chisaki has great durability as he was assaulted by several of Mirio Togata's punches and was able to take them as well as remain fully conscious despite still receiving bad injuries, whereas a simple attack from Mirio was enough to knock out and badly injure two of the Eight Expendables to the point where they could no longer fight. Chisaki showed little reaction to having both of his arms destroyed by the League of Villains
Mask: Like various of his members, Overhaul wears what resembles to be a bird-like beak plague doctor mask. He claims to wear it because he's sensitive to dust.
Gloves: Chisaki wears a pair of gloves along with the rest of his attire. More over he only utilizes his power when he removes them, indicating they serve as a type of limiter on his abilities. In order to keep from obliterating everything he touches.
- Overhaul vs. League of Villains: Undecided
- Mirio Togata vs Kai Chisaki: Interrupted
- Izuku Midoriya, Mirio Togata, & Sir Nighteye vs. Kai Chisaki: Lose
Overhaul is the leader of his organization. He does not appear to have a level of respect or care for his subordinates beyond their use. This was evident when he used one of his subordinates as a human shield and chastises another subordinate for being slow.
Despite how he treats them, the members appear to value Overhaul as their leader and willing to protect him.
Former Head of Shie Hassaikai
Currently, not much is known about the relationship between the two. However, Chisaki appears to greatly respect him. Chisaki is aware that most of those in Shie Hassaikai only stay because of the former boss and not out of love for him, but Chisaki believes that he alone cares about their bedridden boss more than anyone.
Chrono is a member of the Eight Precepts of Death and one of the few members Overhaul does not treat like a disposable object. This is most likely because Chronostasis's abilities are of higher use than most of the members which places him as a valuable asset to the organization.
Mimic is a member of the Eight Precepts of Death. Similar to Chronostasis, Mimic is treated as a valued member of Overhaul's organization and not considered expendable. Mimic is incredibly loyal to Overhaul. Despite his stature and being the General Manager of the organization, Mimic accompanies Overhaul during his exploits and protects him from potential threats.
Eri is an important person to Overhaul. Similar to Chronostasis, Overhaul treats her better than most of his other subordinates because of her use.
From the information gathered by Nighteye's office, it is assumed Overhaul is using Eri's blood to create and sell his Quirk attacking darts. However, the most disturbing aspect is the theorized process; based on Nighteye's investigation, Overhaul supposedly uses his Quirk to destroy and reassemble Eri in order to mass produce his product. From this supposed treatment, Overhaul truly does not care about Eri as a person (or the fact she is his daughter, supposedly) and only sees the value of her because she is the key to his plans.
Eri fears Overhaul, both from his treatment of her to produce his Quirk attacking darts and his killer intent. This fear runs very deep as his killer intent was enough to make her return to his side despite how much she wanted to get away from him.
Overhaul does not show interest in joining the League of Villains due to their apparent lack of planning. He only sees their influence as a means for his motives. The League initially had interest in Overhaul and his organization before coming into a disagreement when Overhaul brought up his motives.
The meeting caused a conflict between the two, resulting in casualties on both sides, further angering the league. Despite this unstable relationship on both sides, Overhaul still saw value in the league and encourages them to figure things out before contacting him again.
Overhaul also treats the league with some level of level-headedness and sentiment, as he wanted to bring out the full potential of the league by having them work under him. He only acted violently when the league threw the first punch and apologized to Mr. Compress for destroying his arm.
However, when he was defeated by Izuku Midoriya and being transported to a hospital Tomura attacked the police escorting him. Overhaul was not fazed by their appearance but he got angry when they stole his quirk drug however, his rage turned to fear as Mr. Compress and Tomura decayed and took his arms. Tomura then taunted the now helpless and powerless Overhaul who made off with his creation which he claimed for himself.
- Overhaul and Tomura Shigaraki have several similarities:
- Both wear plain clothes and a coat but also have unique masks.
- Both their masks have some connection to their character:
- Tomura's hand has some connection to his father.
- Overhaul's plague-doctor mask parallels his mysophobia.
- Both are succeeding leaders to their organization after a previous leader was toppled.
- Both their Quirks have similar attributes:
- Both require direct contact with their hands to touch their target for their quirks to work.
- However, unlike Tomura who needs all five fingers to activate his quirk, Overhaul appeared to only need a finger at the minimum to use his quirk.
- Also, Tomura's Quirk can disintegrate anything while Overhaul's Quirk can disassemble anything (thus destroying them) as well as reassemble them.
- Both Quirks are destructive in nature to their enemy.
- However, Overhaul's Quirk is able to reassemble objects while Tomura's doesn't.
- Both require direct contact with their hands to touch their target for their quirks to work.
- Overhaul's first encounter with the League of Villains bares similarity to Stain's first encounter with the league.
- Both were committing their own acts of violence before being approached by a member of the league.
- Both had some level of interest for the league before revoking their interest after realizing the league's limits, which led to a conflict between them.
- Both ended their meetings in bad taste with the league.
- Both stated that the league had some form of potential and would see how that grows. Though for Overhaul, that potential is more for his own motives.
|Independent||Stain • Giant Villain • Toxic Chainsaw • Trapezius Head Gear • Sludge Villain • Gentle • La Brava|
|Original Members||All For One • Artificial Humans • Kurogiri • Tomura Shigaraki|
|Recruits||Dabi • Himiko Toga • Magne • Moonfish • Mr. Compress • Muscular • Mustard • Nomu • Spinner • Twice|
|Prominent Members||Overhaul • Chronostasis • Mimic|
|Eight Expendables||Rikiya Katsukame • Shin Nemoto • Toya Setsuno • Yo Hojo • Soramitsu Tabe • Kendo Rappa • Hekiji Tengai • Deidoro Sakaki|
|Independent||Kuin Hachisuka • Three Sturm und Drang Brothers|
|Members||Souga Kugizaki • Moyuru Tochi • Raputo Tokage • Mario Kugutsu • Akira Iwako|
|Members||Curator • Zookeeper • Bearhead|