Muzan Kibutsuji (鬼舞辻無慘, Kibutsuji Muzan) is the main antagonist of the Demon Slayer: Kimetsu no Yaiba fantasy action manga and anime series. Muzan is the powerful King of all the Demons, who has the ability to inject his victims with blood that allows him to convert them into more Demons.
Muzan has the ability to change his appearance which made it so easy for him to hide from the Demon Slayers for decades. During his meeting with the Lower Ranks, he was disguised as an elegant woman.