Muzan Kibutsuji is the Demon King and, thus, the primary antagonist in the Demon Slayer anime and manga series. He controls and dictates the actions of all the demons while being the leader of the Twelve Kizuki.
As the Demon Lord, Muzan has lived over a thousand years amongst humankind. But the question stands: how did Muzan become a demon? If he is the progenitor of all demons, who turned him into a demon? This article discusses the origin of Muzan Kibutsuji as the Demon King.
Who turned Muzan into a demon?
The strongest demon to ever exist, Muzan Kibutsuji, drives the plot of Demon Slayer. He kills Tanjiro’s family and turns Nezuko into a demon thereby giving the story the necessary kickstart it requires.
The story of Muzan turning into the petrifying demon he is today dates back to the Heian period in Japan. Ever since his mother conceived him, he has struggled to survive. He was weak in the womb, and his struggle to stay alive caught on when he was born.
As a young boy, he was diagnosed with a mysterious terminal illness. Naturally, his instinct to survive connected him to a doctor. To cure young Muzan, the doctor developed an experimental treatment for him.
Unfortunately, the medicine worsened his condition, making him impatient. When he was about 20 years of age, he turned impatient and killed his doctor in a rampant rage, albeit realizing later that his medicine worked and turned him stronger and more formidable.
He also discerned that he needed to consume human flesh and avoid sunlight to survive. With no humanity left, he easily chose himself over sacrificing innocent people.
Not only that, he also made it his mission to find the cure that would help him walk freely in daylight. To do so, he made various demons and assigned them the task of finding the rare Blue Spider Lily so that he could eradicate his only weakness against the sun and live eternally.
