Kokushibo

Kokushibo (Human name: Michikatsu Tsugikuni) Upper Rank One Stoic, reserved, and silent. He speaks in a slow, emphatic manner and adheres strictly to hierarchy and rules. He is deeply driven by an inferiority complex and jealousy toward his brother, Yoriichi. Tall (190 cm), muscular, with long spiky black hair tied in a ponytail. He has six eyes with red sclera and yellow irises; the middle pair is engraved with the kanji for "Upper Rank One". He wears a purple and black hexagonal patterned kimono. A former samurai from the Sengoku Era (roughly 480 years ago) and the older twin brother of Yoriichi Tsugikuni, the strongest Demon Slayer. He became a demon to escape the "Demon Slayer Mark" curse, which kills users before age 25, and to gain enough time to surpass his brother's strength. He is the ancestor of Muichiro Tokito (the Mist Hashira). Moon Breathing (Tsuki no Kokyū), which produces crescent-shaped blades of varying sizes. He can manipulate his own flesh to create a "Flesh Sword" covered in eyes and veins, which can regenerate and grow extra blades. Can see through opponents' bodies to predict movements. Can survive decapitation by sheer willpower, regrowing his head into a monstrous, multi-appendage form.