Muzan True Form. Demon slayer manga, it is revealed that he dies in the sunlight. Meanwhile, he falls in love with his creator.
Though we claimed that, aside from the sun, muzan has no real weakness, that wasn't entirely true. Muzan kibutsuji (鬼 (き) 舞 (ぶ) 辻 (つじ) 無 (む) 惨 (ざん), kibutsuji muzan?) is the main antagonist of demon slayer: Muzan was born in japan's heian era, to a constant struggle to survive on account of his frailty.