Muzan

Biodata

Feature	Information
Name	Muzan (无惨), Kibutsuji Muzan
Alias(es)	Demon King; Progenitor of Demons
Species/Race	Demon
Gender	Male
Affiliation	Master of the Twelve Kizuki; ruler of Infinity Castle
Occupation/Role	Creator and controller of demons; primary enemy of the Demon Slayer Corps
Status	Deceased; transformed back into a human by Tamayo's medicine and ultimately died 418 421
First Appearance	Chapter 12

Power Progression

Stage / Realm / Level	Chapter	Notes
Demon King	13	Already possessed seven hearts, five brains, extreme regeneration, and flesh-whip attacks; Yoriichi could only weaken and repel him despite severing his neck and vital organs. 13 315
Sunlight-Immune Demon King	403	Absorbed Yuko's lost Asura Blade, a Demon Blade made from the body of a demon who had overcome sunlight, and became immune to the sun. 403 406
“Perfect Ultimate Being”	406	His five brains and seven hearts ceased functioning as protective weak points, merging back into his body; Scarlet Blades and Nichirin decapitation no longer restrained him as before. 406

Background

Muzan originated from the Ubuyashiki bloodline during the Heian period. His existence as the first demon brought a curse upon the Ubuyashiki family: its male members rarely lived beyond thirty unless the clan continued dedicating itself to eliminating him. 66 218 327

Centuries before the main conflict, Muzan encountered Tsugikuni Yoriichi. Yoriichi perceived Muzan's seven hearts and five brains, then used the thirteenth form of Sun Breathing to sever his neck and vital organs. Muzan survived through his overwhelming demonic vitality, but Yoriichi's attacks left scars that later became exploitable weak points. 13 315 392 393

Muzan personally recruited Kokushibo after offering him immortality and a cure for his illness in exchange for becoming a demon. Kokushibo accepted, eventually becoming Upper Rank One and Muzan's most trusted collaborator. 12 41 123

Appearance

Muzan is usually described as pale-faced with crimson eyes and refined clothing, including a black suit or luxurious black kimono. His appearance becomes increasingly grotesque in battle as his body produces whips, tentacles, armor, and mouths. 80 123 148 385 392

• Pale complexion and crimson eyes. 80 123
• Often appears in formal black clothing. 80 123
• Has also appeared in women's attire. 148
• Can reshape his body into flesh-colored whips, thorned tendrils, armor, and enormous mouths. 332 382 385 392

Personality

Muzan is driven above all by self-preservation. He considers survival worth any cost, readily retreats when threatened, and seeks power that will remove every weakness—especially his vulnerability to sunlight. 382 392 403

He views humans as abnormal for pursuing revenge and sees his own killing as natural rather than sinful. He refuses responsibility for the suffering caused by demons, dismissing the Demon Slayer Corps' demand for atonement as meaningless. 376 393

Muzan is contemptuous of most subordinates, treating Lower Ranks as expendable and even regarding Upper Ranks as replaceable tools. His trust in Kokushibo is an exception, though that trust deteriorates after Kokushibo hesitates over Yuko. 79 123 149 371 418

Yoriichi remains Muzan's deepest fear. Yuko's resemblance to the Sun Breathing swordsman repeatedly disrupts his composure and makes him act rashly. 80 124 317 393

Abilities & Skills

Demon Physiology and Regeneration

Muzan possesses a demonic body far beyond that of ordinary demons and Upper Ranks. His original anatomy included five brains and seven hearts, allowing him to survive injuries that would kill other demons. 13 48 194

• Initially overcame the weakness of his neck; sunlight was considered his only reliable method of destruction. 194 325
• Regenerates severed limbs and major bodily damage at extreme speed. 334 401
• Can move his hearts and brains through his body to evade targeted attacks. 394
• Regeneration and combat performance decline when his stamina is exhausted or his cells are damaged by Tamayo's medicine. 410 413 416

Flesh Manipulation

Muzan can reshape his flesh, bones, and blood into offensive or defensive structures.

• Transforms his arms and body into high-speed flesh whips capable of devastating large groups. 13 48 385
• Produced nine bone-covered whips from his back to expand his attack range and counter Yuko's speed. 332
• Creates monstrous mouths that can seize or devour opponents. 392 406 411
• Forms flesh armor and can enlarge his body to break restraints. 388 395
• Uses Blood Demon Art: Black Blood Thorn, generating blood thorns alongside his tentacles for wide-area destruction. 382 394

Shockwave

Muzan can emit powerful, largely invisible shockwaves from his body.

• The shockwaves can throw numerous Demon Slayers away at once and devastate the surrounding terrain. 396 403
• Yuko's Blood Demon Art can reduce, but not fully negate, their impact. 396

Demon Blood Control

As the progenitor of demons, Muzan can grant blood to strengthen or transform others into demons.

• Can rapidly empower demons with his blood and create disposable Lower Rank-level subordinates. 77 79
• Can observe through the cells of demons under his control, though distance weakens this surveillance. 78 124
• Can sense demons carrying his potent blood, including fellow Upper Ranks. 200
• Attempted to forcibly demonize the Hashira, but Yuko's blood contested his control over their bodies. 381

Sunlight Immunity

Muzan's greatest achievement was overcoming sunlight, formerly his defining weakness.

• Achieved sunlight immunity after consuming Yuko's lost Asura Blade. 403 406
• His body resumed regeneration even while pinned beneath sunlight and a Scarlet Blade. 403
• Afterward, the five brains and seven hearts no longer served as defenses for his neck, leaving him with no known conventional anatomical weakness. 406
• Tamayo's human-transformation medicine nevertheless forced his body back toward humanity and led to his death. 417 418

Relationships

• Tsugikuni Yoriichi — His most feared enemy; Yoriichi nearly destroyed Muzan centuries earlier and left scars that remained Muzan's weak points. 13 392 393
• Yuko — Principal opponent during the final battle. Muzan fears her sunlight-resistant evolution, seeks to devour her, and ultimately blames her and her family for his defeat. 329 382 406 417
• Kokushibo — Upper Rank One and longtime collaborator. Muzan trusted him more than any other demon, but grew resentful when Kokushibo hesitated because of Yuko. 41 123 149 418
• Tamayo — Former subordinate turned enemy. She repeatedly poisons Muzan and develops the human-transformation medicine that defeats him. 334 413 417
• Nakime — Trusted subordinate and controller of Infinity Castle. Muzan relies on her spatial Blood Demon Art while disregarding her as ultimately replaceable. 321 371 372
• Ubuyashiki Kagaya — Head of the clan cursed by Muzan's existence and leader of the Demon Slayer Corps opposing him. 66 327 328

Story Role / Major Arcs

Hunt for Yuko

After Akaza's death, Muzan convenes the Upper Ranks and orders Kokushibo to identify and kill the woman responsible. When Kokushibo recognizes the target as Yuko, Muzan becomes alarmed by her connection to Yoriichi and demands immediate action. 123 124

Muzan's concern intensifies after learning that Yuko has overcome sunlight. He searches for her and the Demon Slayer Corps while dismissing the possibility that she could truly rival Yoriichi. 317 318

Infinity Castle Battle

Muzan confronts Ubuyashiki Kagaya and Yuko, who openly declares that she has achieved Muzan's dream of surpassing sunlight. He orders Kokushibo to attack her, but Yuko suppresses Upper Rank One and then wounds Muzan himself. 327 328 329

He drags the conflict into Infinity Castle through Nakime's Blood Demon Art, intending to exploit the castle's lack of daylight. While fighting Yuko and the Hashira, he reveals his disregard for the Upper Ranks and considers rebuilding his demon army if necessary. 331 371 372

Final Battle and Defeat

After returning to the surface, Muzan battles Yuko, the Hashira, and the Demon Slayer Corps until dawn. Tamayo's poison inhibits his regeneration and ability to split, while Yuko's blood repeatedly restrains and weakens him. 376 394 414

The Corps pins Muzan beneath the rising sun, but he survives by absorbing the power of Yuko's lost Asura Blade and becomes immune to sunlight. His newfound power initially overwhelms the Hashira and removes the effectiveness of his former weak points. 401 403 406

Tamayo's human-transformation medicine eventually forces Muzan back into a human body. Even while dying, he tries to take Yuko down with him, but Yuko resists his provocation and counteracts his poison. Muzan dies in agony, and his death is later confirmed by the Corps. 417 418 421

Notable Quotes

“Why not become a demon? As long as you become a demon, you can possess infinite years.” 12

“I don't believe I've committed any mistakes.” 393