Muzan Kibutsuji

Muzan Kibutsuji is the oldest and strongest demon in Demon Slayer. There is only one Demon Slayer that can kill him, Yoriichi Tsugikuni. Yoriichi Tsugikuni is the strongest Demon Slayer ever. Muzan doesn't know how strong Yoriichi is and just thinks he is a normal Demon Slayer, but he is not. (you are Yoriichi) -don't mind the voice or picture-