Muzan Kibutsuji is the primary antagonist of Kimetsu no Yaiba: Demon Slayer. He is the Demon King, the first of his kind and the father of all demons. Muzan is also the leader of the Twelve Kizuki, a group of the world's twelve most powerful demons who report directly to him.
Muzan struggled with ailments throughout his childhood, which led to his thanatophobia. Muzan was diagnosed with a sickness as a young guy that would kill him before he turned 20. Muzan was given a special prototype medicine by the doctor who was treating him, but it looked to be ineffective.
Muzan was enraged by his deteriorating condition and killed his doctor. He only realised the drug was working after killing the doctor, and that it had helped him build a robust body. He was aware that he would have to eat human flesh to survive, but he was unconcerned about this. On the other hand, hi more significant concern was his inability to walk in the sunshine since it severely burnt him.
He realised how much he regretted killing the doctor before he could conclude his treatment with his "Blue Spider Lily" medicine at this point. He looked for the flower all over the country but couldn't find it. As a result, Muzan began to produce additional Demons and planned to disperse them over the world, hoping that one of them might eventually discover a means to defeat the sun or, at the very least, aid him in his search for the Blue Spider Lily. This yearning to be in the sun once more became his sole purpose, and he spent hundreds of years pursuing it.
He crossed paths with Tamayo and Kokushibo, turning them both into demons. He also has a confrontation with Yoriiichi whom he comes to fear for the rest of his long life.
Who is Muzan's wife?
During the Heian period, Muzan married five different women after becoming a demon. However, as a demon, he verbally tortured all five of his wives to the point where they all committed suicide as a result of his lack of empathy and compassion.
Over time, Muzan blends with human culture to preserve his life. He has a loving wife and daughter in the time in which the story is set, but he is only in the marriage for the purpose of survival. Tsukahiro is Muzan's wife's name.
Muzan is cold-blooded, vicious, frightening, and incredibly smart. He finds little value in any human he has met, and he has little regard for his own subordinates. He is rarely shown unhappy or cheerful, and on most occasions, he appears absolutely monotonous and indifferent, even when he murders his own subordinates.
His inflated ego and inflated feeling of self-worth are so huge that he can't take being teased or corrected in any way, believing that others exist just to serve him. It also implies that he rarely takes any adversary or threat seriously.
Muzan brutally murdered a pair of drunk men for being rude to him, all while proclaiming his own perfection and superiority over them. In his pettiness, he refuses to accept any humiliation and will do whatever he wants until the humiliation is removed.
Muzan is immensely cowardly behind the plethora of masks he wears, fully counteracting his facade of voracious ego and drive for perfection. After Yoriichi, Muzan avoided any direct confrontation with the demon-slaying corps at all costs and sent his underlings to deal with them instead.
When Muzan is cornered, his normally calm, haughty, and superior demeanour crumbles, allowing dread and fear to take hold as he fiercely fights for his life, resorting to more extreme tactics to protect himself. Aside from Muzan's flaws, he has consistently demonstrated a strong affinity for both high fashion and advanced education.
Why Does Muzan Want To Kill Tanjiro Kamado?
Muzan's resolve to kill Tanjiro arose from his loathing for Yoriichi Tsugikuni, his prior rival. Muzan knew he was a Sun Breathing user after recognising Tanjiro's earrings in Asakusa, and that he was a wielder of Yoriichi's tremendously powerful technique, which Muzan had pledged to eradicate after it nearly killed him.
This is why the Demon Lord felt intimidated when he first saw Tanjiro and went frenzied in his attempts to murder him throughout the course of the story.