Muzan Kibutsuji (鬼き舞ぶ辻つじ 無む惨ざん, Kibutsuji Muzan?) He is the Demon King, the first of his kind, and the progenitor of all other demons in existence. A millennium ago during the Heian Era, Muzan was turned into a demon during an experimental treatment trying to cure his terminal illness,Muzan is a tall man with a lean muscular build along with an unnaturally pale skin complexion along with an handsome face.Muzan is cold-hearted, ruthless, intimidating, and exceptionally intelligent.kind with you