Muzan Kibutsuji, the enigmatic and horrifying figure in the world of Demon Slayer: Kimetsu no Yaiba, stands as the embodiment of ultimate evil. As the original demon and the Demon King, Muzan's reign of terror over Japan spanned a millennium, setting the stage for the events in Demon Slayer. Though nearly immortal, Muzan was not always a demon.
With a power that instills fear in even the deadliest of demons, Muzan possesses the ability to survive decapitation and the total destruction of his body. Furthermore, he has the capacity to create and control other demons, making him an incredibly formidable adversary. Muzan is a nightmarish entity beyond comprehension, yet beneath his devilish exterior lies the remnants of the man he once was—a human. Though his true humanity may be difficult to discern, it undoubtedly raises the question: how did Muzan become a demon?
The Reasons Behind Muzan's Transformation into a Demon
During Japan's Heian Period, roughly 1,000 years prior to the Taisho Period, during which the anime and manga are set, Muzan Kibutsuji was declared stillborn after his heart stopped beating multiple times inside his mother's womb. As he was about to be cremated, Muzan coughed and squirmed on the pyre, indicating this young, sick infant still had the will to live. However, Muzan would never fully escape his intimate relationship with death.
As a young man, he was diagnosed with a terminal illness that would take his life before he reached his 20th birthday. Refusing to surrender to death, Muzan sought out a physician who attempted to give the dying young man a few more years of life by experimenting on him. As someone who'd spent all of his short life clinging desperately to survive, it wouldn't be long before he discovered how far he would go to stay alive. He'd give up anything, even his own humanity.
How Did Muzan Become a Demon?
After the physician treated Muzan with medicine made from a flower known as the Blue Spider Lily, Kibutsuji became enraged at the lack of results and murdered his doctor. As soon as Muzan spilled the doctor's blood, however, he realized he had gained incredible, inhuman strength. Additionally, Muzan instinctively realized that he would die if he were ever to be exposed to sunlight. Whatever medicine the physician had crafted using the Blue Spider Lily had effectively granted Muzan immortality, transforming him into the world's first demon.
Muzan quickly began to crave human flesh and had no issue devouring humans to assuage his hunger. However, while Kibutsuji openly accepted the gifts and costs of becoming immortal, he remained humiliated by his inability to survive exposure to sunlight. Muzan had spent his entire life on death's door, and now that imminent death no longer loomed over him, he found himself trapped by his new weakness, only able to live his life in the dark. Muzan was intoxicated by his immense power as a demon but refused to accept anything other than total immortality as the perfect being so that death would forever remain a stranger to him.
Muzan's Motivations Are All Too Human
Having obtained immortality through the power of the Blue Spider Lily, Muzan relentlessly pursued methods to eradicate his vulnerability to sunlight. However, his quest faced a significant setback as the doctor's research notes, containing crucial information on the flower's location and usage, were lost upon the doctor's demise. Throughout the 1,000 years following his rebirth as a demon and the events of present-day Demon Slayer: Kimetsu no Yaiba, Muzan failed to locate the elusive Blue Spider Lily.
Initially, Muzan focused on creating more demons in the hopes that one of them would be born with immunity to sunlight. However, he also employed them for various other purposes. Among the Twelve Kizuki, the Upper Ranks of the demon organization, Muzan appears to harbor a certain level of trust or affinity. He demonstrates a particular fondness for Akaza, permitting his refusal to harm women and entrusting him with the task of continuing the search for the Blue Spider Lily. Muzan also exhibits genuine trust in Kokushibo, the First Upper Rank, as they once embarked on a journey across Japan, eliminating practitioners of Sun Breathing—a unique Breathing Style capable of inflicting significant and lasting harm on Muzan's body.
While both demon slayers and other demons justifiably fear the malevolent Demon King, Muzan's only fear lies in reverting to the weak and dying creature he once was in his youth. Despite reveling in the bloodshed and suffering caused by him and his demons, Muzan does not seek conquest or destruction; his ultimate desire is to become the perfect being. Throughout his long existence, he has committed countless unimaginable acts of evil, yet his motivation remains fundamentally human: fear of death.
Demon Slayer: Kimetsu no Yaiba is available to stream on Crunchyroll, Hulu, and Netflix. It is also available to purchase from streaming sites like Amazon Prime Video, Google Play, and Apple TV. The manga is available in English from MangaMonster.
