Muzan Kibutsuji

Demon is a Demon, the first of his kind, and the progenitor of most other Demons. He is also the enemy of the Kamado family. He is the one that killed the Kamado family, turned Nezuko Kamado into a demon and made Tanjirou Kamado an orphan.

Appearance
He looks like a man in his late twenties. Has curly black hair and eyes somewhat small, his pupils are vertical like cat eyes and plum red. Has on a white hat with red ribbon and a somewhat extravagant outfit.

Personality
Muzan is a ruthless individual that wants his every plan to be perfect. He isn't kind to his progenies only if they failed a mission or being incompetent. Also gives praise to those that are successful in their missions. He does not take his enemies seriously. He also dislikes being questioned and ordered by his progenies.

History
He was inflicted with disease and will die before the age of 20. His disease became worse. He was treated by a doctor who gave him medicine, Blue Spider Lily, that can make his body stronger but it turned him a demon. That in result he can't walk during daylight.

Asakusa Arc
Traveling through a crowd in Asakusa with his family, Muzan is accosted by an angry Kamado Tanjirou. His daughter asked him who the young Demon Hunter was, and he asked the youth if there was something he wanted from him. His wife then approached them, asking if Tanjirou was somebody familiar to their family. He denied this, wondering if the youth had mistaken them for somebody else. He then quickly slashed a passing man, turning him into a Demon.