Kokushibo

Kokushibo is a major supporting antagonist of Demon Slayer: Kimetsu no Yaiba. He is a demon affiliated with the Twelve Kizuki, holding the highest position, Upper Rank One. During the Sengoku Era nearly five centuries ago, Kokushibo was a human by the name of Michikatsu Tsugikuni, a former Demon Slayer, and the older twin brother of Yoriichi Tsugikuni, the strongest Demon Slayer that had ever existed. Kokushibo is also the ancestor of Muichiro Tokito and Yuichiro Tokito and the one responsible for turning Zenitsu Agatsuma's senior, Kaigaku, into a demon and joining the Twelve Kizuki. Kokushib...