Kai Chisaki

"There are so many capable men and all they can think to do is rob a convenience store? Kinda weird. You'd think a group this big might just, y'know...have bigger goals than that. You're all sick. And you need a cure."

- Kai Chisaki displeased with Team Reservoir's actions in Unleashed.

Kai Chisaki (治崎 廻 Chisaki Kai?), also known by his villain name, Overhaul, is a villain from the manga series, My Hero Academia. He is the leader of the Eight Precepts of Death, a Yakuza group of villainous Quirk users and the main antagonist of the Internship Arc.

Personality
Chisaki appears to have mysophobia, as he's under the delusion that everybody around him is sick and hates being touched. This is shown when he kills Magne and severs Mr. Compress's arm simply for trying to touch him. He is also shown to be constantly scrubbing his arm, in fear of any contamination caught onto him.

He is shown to be cruel and sociopathic. After killing Magne, he was only concerned about getting his blood on him. He uses his Quirk to disassemble and reassemble his daughter, Eri, so that he could make Quirk suppression bullets. He will do anything to make things go his way, like showering Eri with gifts so that she'll comply with his orders, and exploiting suicidal people to be expendable pawns. It is even implied that he got his father sick so that he could lead the Yakuza.

Ever since All For One's downfall, Chisaki has plans of becoming the next ruler of the underworld, making him an instant rival of Tomura Shigaraki. Despite this, he is willing to negotiate agreements with him, as means for him to accomplish his goals. He also has a huge hatred for Quirks, as his goal is to destroy them by creating Quirk Destroying bullets, using Eri's Quirk to assemble them.

Despite his insanity, he has shown to express some sort of sentiment to the League of Villains, as he wanted to bring out the full potential of the league by having them serve under his command. He only attacked when the league decided to attack first, and even apologized for destroying Mr. Compress' arm.

Story
At some point before his first appearance, he was a street child taken in by the Yakuza's boss. Hoping to repay him for his kindness, he has been developing bullets that could erase somebody's Quirk that he could sell on the black market. To achieve it, he used his Quirk, Overhaul, to take apart and reassemble a girl named Eri, who has the power to reverse a person's physical state. However, the Boss found Chisaki's actions unethical. Believing his father to be a fool, he makes him ill so that he could lead the Yakuza and distribute the Quirk Erasure Bullets.

He first appears when stopping a group of villains called the Reservoir Dogs, believing them to be sick and in need of curing. He meets Tomura Shigaraki and tells him about how he hopes to rise in the criminal underworld after the power vacuum set by All For One's arrest, much to Shigaraki's annoyance. He offers a merger with the League of Villains, but Magne is against the offer. After Magne tries attacking Chisaki, he blows up his upper body, and then severs Mr. Compress's arm after he retaliates. When Shigaraki tries to retaliate, Chisaki orders one of his minions to act as a human shield, protecting him. After Chisaki and Shigaraki calm down, they eventually agree to an alliance.

One day, during Izuku's internship with Mirio, Eri manages to escape Chisaki's clutches. Realizing they were in a situation where they couldn't stop him, Izuku grudgingly lets Chisaki take Eri back. When Chisaki returns to his lair, he kills another one of his lackeys for failing to restrain Eri.

When the heroes raid the Eight Precept's hideout, he is seen talking to his father, assuring him that everything will be alright. He encounters Togata Mirio, who manages to put up a decent fight. He has an underling shoot Togata with the Quirk nullifying bullet, but that doesn't stop him. When he encounters Izuku, in an act of desperation, he fuses with Shun Nemoto. After a brief fight, Eri uses her Quirk to defuse them.

Chisaki then fuses with Rikiya. After learning what Eri could do, Izuku lets Eri ride his back so that he can use One For All at 100% without hurting him. With Chisaki defeated and arrested, the police convoy taking him to prison is intercepted by the League of Villains. When Shigaraki has Chisaki cornered, he asks if he's going to kill him, but he has something worse in mind for him. Shigaraki has had a grudge against him for killing Magne and severing Mr. Compress's arm. As payback, he and Compress sever his arms and then shoot him with a Quirk Erasure Bullet, ensuring that he could never use his Quirk again. The League of Villains then make off with the remaining Quirk Erasure Bullets while Chisaki is left in a permanently helpless state.

Former Powers and Abilities
Kai Chisaki has currently lost the ability to activate his Quirk, as both his arms were destroyed by Tomura Shigaraki and Mr. Compress.
 * Overhaul: Chisaki's Quirk allows him to disassemble and reassemble anyone/anything through physical contact. He is able to kill people instantly with this Quirk as shown when he blew up Magne's and Rappa's upper bodies off completely. Unlike Shigaraki's Quirk, however, Chisaki seems to have control of his to a certain degree, as he was able to only destroy Mr. Compress' arm, while he utterly destroyed Magne. However, he is shown to wear gloves, in order to curb the effects of his Quirk, implying that he has no control over the activation of it. Chisaki is also capable of reviving people from the dead with this Quirk, as he was able to reassemble Rappa's body back together. There also seems to be no limit to this, as he was able to bring back Rappa's body back together five times, after challenging him to a fight. Chisaki is also able to use this Quirk as means of fusing with others, as demonstrated on Shin Nemoto and Rikiya Katsukame.

Trivia

 * Kai Chisaki shares similarities with another My Hero Academia villain, Tomura Shigaraki.
 * They are both villains who strive to become the next ruler of the underworld, leading a villainous organization as support. Their Quirks involve coming in contact with people and killing them by reducing them to bits.
 * However, unlike Shigaraki, Chisaki is a matured, experienced adult who's already had his plans ready from the get go. However, Shigaraki's maturity has slowly shown to evolve after Chisaki's defeat. Chisaki's Quirk also allows him to reassemble a person's body back to normal.