Kai Chisaki

Kai Chisaki, also known as the villain Overhaul, was a yakuza and the leader of Shie Hassaikai. He serves as the main antagonist of the Internship Arc.

Appearance
Overhaul looks like a typical man in his 20s with short, brownish hair, eyes that are often bloodshot, and several ear piercings.

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. Compress takes the other.

Fusions
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.

Personality
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 a 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. This is ironic considering, he often uses his quirk to settle things. 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 have little care if not none at all 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 his quirk drug and both of his arms and taunted him for his lack of power. His facial expression was that of horror, as he was taunted for now ironically being the very thing he wanted on others.

Abilities
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. Later on, he was able to survive punches from Deku who was wielding One For All at a 100%. Chisaki showed little reaction to having both of his arms destroyed by the League of Villains.

Quirk
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.

Equipment
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. Moreover, 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.

Internship Arc

 * Overhaul vs. League of Villains: Undecided
 * Mirio Togata vs Kai Chisaki: Interrupted
 * Izuku Midoriya, Mirio Togata, & Sir Nighteye vs. Kai Chisaki: Lose

Trivia

 * Overhaul's characters in his name are composed of "治" (chi, lit. "govern, regulate, administer"), "崎" (saki, lit. "promontory, cape, spit") and "廻" (kai, lit. "revolve, return, curving").
 * "廻" (kai) notes his quirk “Overhaul” that can disassemble and reassemble anything that he touches.
 * “chi” (治) in his surname has different meanings attached,
 * It could mean (to treat, to cure disease) how he believes everyone is sick, obsessed with finding a cure.
 * (to research, to specialize in a topic) noting his research on destroying quirks.
 * (to punish, to discipline, to teach someone a lesson) referring how Overhaul treats Eri as a subject for his bullets and force her to obey through intimidation and how he was hoping to use the quirk destroying drugs to control society through fear.
 * (to exterminate, to kill) seen several times that he used his quirk to kill others.
 * 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 in 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.
 * 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 in 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.

Quotes

 * (To Team Reservoir Dogs) "You guys have an illness. Illnesses must be cured."
 * (To Midoriya Izuku) "When someone lays a finger on me, I can't help but feel the need to cleanse myself."