Muzan

Biodata

Feature	Information
Name	Muzan Kibutsuji (鬼舞什)
Alias(es)	Demon King; Progenitor of Demons; Scum Boss
Species/Race	Demon
Gender	Male; can assume different outward appearances, including that of a young woman 51 159 176
Affiliation	Infinity Castle; Twelve Kizuki
Occupation/Role	Ruler of the demons; creator and commander of demon subordinates
Status	Deceased; killed when Tsugikuni Kuuga and Tanjiro Kamado destroyed his final heart with synchronized Sun-Breathing at sunrise 190
First Appearance	Mentioned: Chapter 1; physical appearance: Chapter 51

Background / History

Muzan is the demon leader whose name alone inspires terror among his subordinates. When Tsugikuni Kuuga falsely claims that Muzan has arrived, the Earth Demon immediately trembles, turns around, and kneels, allowing Kuuga to escape 1.

From the Infinity Castle, Muzan governs the Twelve Kizuki through fear, blood, and arbitrary punishment. After repeated losses to the Demon Slayer Corps, he berates his surviving demons, disciplines Douma for failing against Kuuga, and abandons his prior intention to eliminate every Lower Rank in favor of rapidly strengthening useful subordinates with more of his blood 51. He personally injects Winged Bat with enough blood to transform it into an Upper Rank, though the process risks destroying demons unable to endure it 52.

Kuuga's Sun-Breathing makes him a priority target. Muzan orders Kokushibo to eradicate everything connected to Sun-Breathing and offers any demon who kills Kuuga more blood and a possible Upper Rank promotion 51 55. His hatred of Sun-Breathing stems from the lasting trauma Yoriichi Tsugikuni inflicted on him; despite dismissing Kuuga as inferior to Yoriichi, he repeatedly devotes resources to eliminating him 51 62.

Muzan also experiments on his own demons. He authorizes a mutagenic drug made from his blood and other medicines, with Daki becoming its first test subject. The experiment turns her into a bloodthirsty, unstable creature that absorbs Gyutaro and loses her individuality 139 140. He later reacts with ecstatic delight to Nezuko Kamado's immunity to sunlight, deciding that consuming her would achieve his thousand-year goal more directly than seeking the Blue Spider Lily 159.

Rather than immediately assaulting the Demon Slayer Corps headquarters, Muzan appoints Nakime as Upper Rank Four and orders demons to remain hidden while he creates more forces for a future offensive 159. His surveillance eventually locates the Ubuyashiki residence, but Kuuga uses Nakime's eyeballs to lure him into a six-month trap while disguised as Oyakata-sama 176.

Muzan survives Kuuga's kunai barrage and the destruction of the Ubuyashiki estate, but Tamayo betrays him and administers a poison hidden within her body 177. The drug rapidly ages him, interferes with his abilities, and leaves him vulnerable to the Demon Slayer Corps' coordinated assault 178 186 189. After killing Nakime to collapse the Infinity Castle and return the battle to the surface, he makes a final attempt to escape sunrise 186 190.

Kuuga and Tanjiro pursue him with synchronized Sun-Breathing, repeatedly destroying his hearts and brains until his last heart is severed. As he dies, Muzan attempts to preserve the Demon King's legacy by forcing his will onto Tanjiro 190.

Appearance

Muzan has pale skin, blood-red or plum-red eyes, and the ability to alter his apparent age, gender presentation, and body shape 51 159 176.

• Appears as a young woman in a black kimono decorated with blood-red spider-lily patterns 51.
• Appears as a pale young man in wealthy-family attire after learning of Nezuko's sunlight resistance 159.
• Visits the Ubuyashiki residence as a tall, black-haired young man with paper-pale skin and plum-red eyes 176.
• After decomposing much of Tamayo's poison, assumes a grotesque demon form with white hair, red eyes, mouths full of teeth across his face and body, and intense killing intent 188.

Personality

Muzan is arrogant, contemptuous, and violently intolerant of weakness. He regards failed subordinates as disposable “trash,” kills or punishes demons who disappoint him, and values them chiefly as tools for his ambitions 51 75 102.

His greatest obsession is overcoming sunlight and attaining what he considers perfection. Nezuko's sunlight resistance fills him with exhilaration, while the prospect of acquiring it makes him willing to delay his offensive in order to build a larger demon force 159. He shows no concern for human life, casually killing his adoptive mother and a maid when they witness his transformation 159.

Despite presenting himself as invincible, Muzan is deeply affected by Yoriichi Tsugikuni and Sun-Breathing. Kuuga's imitation of Yoriichi unsettles him, and his repeated insistence that Kuuga is not Yoriichi reveals how strongly that past encounter still governs his fears 176 186. His pride repeatedly leaves him vulnerable to deception, including Kuuga's trap and Tamayo's betrayal 176 177.

Abilities & Skills

Demon Blood Bestowal and Enhancement

Muzan can turn humans into demons and increase a demon's power by injecting them with his blood.

• Excessive blood causes a recipient's body to swell and may kill them if they cannot endure it 52.
• His blood transformed Winged Bat into Upper Rank Nine and granted it massive wings 52.
• He uses blood rewards to encourage demons to hunt Kuuga, offering the possibility of Upper Rank status 55.
• His blood is a component of the mutagenic drug used on Daki 139.
• He injected Nezuko with demon blood, though she survived where other victims did not 62.

Black Blood Thorn

Muzan manifests black thorns and spikes as a primary ranged Blood Demon Art.

• Can launch thorns to attack targets such as Tamayo from a distance 178.
• Uses large numbers of thorns to suppress multiple Demon Slayers simultaneously 178 189.
• Can create a black-thorn prison around an area when emerging from underground 188.

Whip-like Tendrils

Muzan can extend long, barbed tendrils from his back, legs, and thighs.

• The tendrils are described as scorpion-tail-like, approximately seven meters long, and hard enough to deflect or sever thousands of kunai 177.
• He can deploy more than a dozen tendrils at once, producing sonic booms and cracking the ground 178.
• He uses them to target wounded opponents and overwhelm the Demon Slayer Corps during the final battle 189.
• Extreme exhaustion eventually prevents him from using them while fleeing the sunrise 190.

Regeneration and Altered Biology

Muzan possesses extreme regenerative capacity and multiple vital organs.

• He rapidly regenerates damage that would be fatal to ordinary demons and humans 177 178.
• He has five brains and seven hearts, making conventional decapitation insufficient 178.
• He can split into thousands of pieces to survive; Tamayo's poison later prevents him from doing so 189 190.
• Tamayo's poison rapidly ages him and forces his cells to repeatedly die and regenerate 178.
• Although he decomposes much of the poison, he remains physically weakened after aging beyond ten thousand years 186 189.

Shockwave

Muzan can release a powerful shockwave centered on his body.

• The attack blasts nearby opponents away and causes bleeding from their seven orifices even through defensive techniques 178.
• It incapacitates most of the Demon Slayer Corps during the final battle 189.
• The technique weakens as Muzan's aged and poisoned body deteriorates 190.

Demon Command and Intelligence Network

Muzan commands demons through a hierarchy centered on the Infinity Castle.

• Nakime reports intelligence to him through her Eyeball Clone network 159 176.
• He issues orders, promotions, punishments, and operational restrictions to the Twelve Kizuki and lesser demons 51 159.
• His control is not absolute: Great Tengu resists his authority and cannot be killed by him despite repeated attempts 75.

Relationships

• Tsugikuni Kuuga — Primary enemy and Sun-Breathing user targeted by Muzan's demon forces; Muzan repeatedly dismisses him as inferior to Yoriichi while treating him as a major threat 51 55 176 190.
• Yoriichi Tsugikuni — Muzan's enduring trauma and benchmark for power; Muzan believes no one can equal him 51 62.
• Tamayo — Former subordinate who betrays him with a body-hidden poison designed to turn him human and accelerate his aging 177 178.
• Nakime — Servant and intelligence operative whose Eyeball Clones locate targets; Muzan appoints her Upper Rank Four, then kills her to collapse the Infinity Castle 159 176 186.
• Kokushibo — Upper Rank One entrusted with eliminating Sun-Breathing-related threats; Muzan recognizes his assessment of Kuuga's potential but initially rejects it 51 57.
• Douma — Upper Rank demon punished for failing against Kuuga 50 51.
• Rui — Demon rewarded with additional blood and later promoted to Upper Rank Three after providing the Corps headquarters’ location 102 123 124.
• Nezuko Kamado — Sunlight-immune demon whom Muzan seeks to consume to fulfill his ambition of overcoming the sun 159 161.
• Great Tengu — Uncontrollable demon who openly disrespects Muzan; Muzan manipulates him by directing his hatred toward Sun-Breathing users 75.

Story Role / Major Arcs

Demon Hierarchy and Kuuga Hunt

Muzan's name establishes the terror governing demons from the opening conflict. Following the defeats of multiple Lower and Upper Ranks, he reorganizes his forces, empowers selected demons with blood, and makes Kuuga's death a pathway to greater power for any demon capable of achieving it 1 51 52 55.

Nezuko and the Swordsmith Village Aftermath

Muzan's experiments contribute to Daki's monstrous transformation, while Nezuko's sunlight resistance becomes the breakthrough he has pursued for a thousand years. He responds by concealing demon activity, strengthening his numbers, and preparing a delayed assault on the Demon Slayer Corps 139 159.

Assault on the Ubuyashiki Residence

Muzan follows Nakime's intelligence to what he believes is Oyakata-sama's unguarded residence. Kuuga's disguise, poisoned kunai barrage, explosives, and Tamayo's betrayal turn the assassination attempt into an ambush 176 177.

Final Battle

Weakened by Tamayo's poison but still overwhelmingly dangerous, Muzan fights Kuuga, Kyojuro, Gyomei, and the other Demon Slayers. He retreats into the Infinity Castle to recover, kills Nakime to bring the conflict back to the surface, and battles desperately until sunrise 178 179 186 189.

Death

Unable to split apart because of Tamayo's poison, Muzan flees from the rising sun. Kuuga and Tanjiro pursue him with synchronized Sun-Breathing, destroy his remaining vital organs, and kill him. In his final act, Muzan attempts to pass his will on to Tanjiro 190.

Notable Quotes

“You bunch of trash, what use are you?!” 51

“Why bother looking for the trash Blue Spider Lily? Eating Nezuko will solve everything.” 159

“I am the ultimate lifeform! How could I be killed by two humans?” 190

Trivia

• Muzan's subordinates react so fearfully to his name that Kuuga successfully uses it as a bluff more than once 1 24.
• He considers wisteria deeply unpleasant and reacts with visible disgust to its scent at the Ubuyashiki trap 176.
• Muzan's own arrogance is directly exploited by Kuuga, who counts on him underestimating humans and wasting time talking before attacking 177.