Hishigi’s medical knowledge enables him to manipulate a body's cells at the molecular level; he can alter, destroy, or even create new tissue. By applying this knowledge, he was able to implant dozens of Medusa Eyes into his own body to prolong his life after he contracted the Death Disease decades before the events of the manga. During Akari's time with the Mibu, Hishigi also implanted a single Medusa Eye in her left hand. The Medusa Eye possesses highly destructive properties and almost no weaknesses. It can only be destroyed by its own reflection.