Quirk-Destroying Drug

A chemical compound that permanently erases a person's Quirk.

The Quirk-Destroying Drug is a chemical compound developed by the Shie Hassaikai, a yakuza group, that is designed to permanently erase a person's Quirk. It is made by experimenting on Eri, the granddaughter of the group's former boss, whose "Rewind" Quirk reverts a living body to an earlier state; the work is driven by the young boss Kai Chisaki, known as Overhaul. The drug is a central plot device during the conflict between the Shie Hassaikai and multiple Hero agencies, as it poses an existential threat to both heroes and villains by permanently removing their superpowers. Its existence drives the motivations of the yakuza and leads to a high-stakes raid to save Eri and prevent the drug's mass production.

Quick Facts

Creator: Shie Hassaikai
First major appearance: Shie Hassaikai Arc
Current status: Remaining drugs stolen by League of Villains

Lore & Background

The Quirk-Destroying Drug was created by the Shie Hassaikai, a yakuza group experimenting on their boss's granddaughter Eri to produce Quirk-Destroying Drugs. Overhaul also has a serum, and the drug is delivered in bullets. Overhaul's aim is to bring the yakuza back to power: he plans to monopolise the drug and its serum on the black market. The drug is so feared that multiple Hero agencies, led by Sir Nighteye's team, raid the Shie Hassaikai's base to save Eri and destroy the remaining drugs. During the raid, Nighteye is killed, Mirio Togata is de-powered by the drug, and the remaining drugs are stolen by the League of Villains. Eri is later adopted by U.A. staff, and she trains her Quirk to eventually restore Mirio's Quirk.

Reader's Guide

The drug takes away the Quirk of the person it hits; Mirio Togata loses his Quirk to it during the raid. Later Tomura Shigaraki throws one of the stolen bullets into Eraser Head's leg, and Aizawa cuts the leg off before the drug can spread. Dr. Garaki reverse-engineers the drug into one that works like Eri's Quirk, which All For One uses on himself in the final battle. The only known method to reverse its effects involves the "Rewind" Quirk, which can restore the body to a previous state before the damage occurred.