Muzan

Biodata

Feature	Details
Name	Muzan Kibutsuji (无惨) 1
Alias(es)	Kibutsuji Xu Ming; Xu Xing; Tsukiin; Tsukihiko; Tsukihana 11 54 104 147
Species/Race	Demon King; later described as a Half-Demon 1 53
Gender	Male
Affiliation	Demon faction; founder of the Twelve Kizuki and Star Ranks; infiltrator within the Demon Slayer Corps 42 54 56
Occupation/Role	Demon King, physician under assumed identities, swordsman, mentor, and demon administrator 11 53 130
Status	Active 263
First Appearance	Chapter 1

Power Progression

Stage / Realm / Level	Chapter	Notes
Demon King	1	Begins as the ruler of demons, with authority over demon minds and access to the original Muzan's accumulated memories.
Clear World — unstable access	11	Enters the Clear World only intermittently, succeeding roughly five or six times over more than a decade.
Sunlight-tolerant demon	34	The Blue Spider Lily treats his condition: he can endure sunlight and consume ordinary food, though eating humans still strengthens demons.
Half-Demon	53	Is explicitly described as a Half-Demon and can kill other Half-Demons by injecting his blood directly into their heads.
Crimson Blade	218	Activates a Crimson Blade directly rather than undergoing conventional training, then explains its principles to the Hashira.
Blood extraction and human restoration	228	Refines his blood control enough to remove his demon blood from a transformed human, restoring the subject's humanity and physical health.

Background

Muzan inherits the position and memories of the original “Scum Boss,” a Demon King whose cruel rule left many demons dependent on his blood. Early in his reign, he keeps Yanagisawa Noriyuki—a physician turned into a demon for his medical skill—as a subordinate, but is notably more tolerant of Noriyuki's practice of treating people and feeding only on the wicked. 1

Rather than indiscriminately expanding his forces, Muzan removes subordinates he considers unsuitable and begins remaking demon society around his own rules. He transforms the impoverished Maruoka siblings, gives them a mission to build an equal society, and encourages demons to avoid harming innocents while pursuing bandits, corrupt nobles, or other targets. 5 6

Concerned by the threat posed by Yoriichi and the Demon Slayer Corps, Muzan studies swordsmanship across numerous dojos and learns disciplines including swordsmanship, boxing, archery, hidden weapons, and hand-to-hand combat. He also turns the dying physician Tamayo into a demon, valuing her medical knowledge and potential support. 7 8 9

Appearance

Muzan ordinarily conceals his nature behind human identities, fashionable clothing, and changing appearances. When revealing himself, his body becomes visibly inhuman and weaponized. 8 66

• Crimson pupils and sharp fangs appear when he exposes his demonic identity. 8
• His arms can reshape into giant, toothed maws capable of swallowing victims whole. 4 8
• He manifests blood-red, whip-like appendages from his back for restraint, piercing attacks, and crowd control. 11
• He can take the appearance of a child, using the identity “Tsukiin” to obtain training from Sakonji Urokodaki. 104
• He maintains an interest in contemporary fashion and considers himself ahead of his era in dress. 66

Personality

Muzan is simultaneously calculating and extremely idle. He spends long periods reading, lounging in rocking chairs, eating snacks, and following new technology, yet becomes highly proactive when a threat, an entertaining scheme, or a useful project captures his interest. 1 28 66

He is controlling toward demons but does not govern solely through fear. Muzan gives valued subordinates blood, education, roles, and long-term projects; he also establishes rules against killing innocents. His kindness is inconsistent, however, since he readily manipulates others, uses people as bait, and violently punishes betrayal or disobedience. 5 6 22 76

Muzan has a childish, provocative streak. He enjoys humiliating opponents, especially Half-Demons and Demon Slayers, and frequently avoids direct danger by fleeing, using subordinates as obstacles, or letting others fight on his behalf. 75 92 244

Abilities & Skills

Demon Physiology and Body Manipulation

Muzan possesses a demon body with extreme physical strength, speed, durability, regeneration, and the ability to reshape his flesh into weapons.

• Pins and crushes large demons with physical force alone. 2
• Catches volleys of arrows and evades Nichirin Blade strikes at close range. 4
• Creates maw-like arms, claws, and whip-like appendages for devouring, impaling, and restraining targets. 8 11
• Ordinary blades cannot pierce his skin, but wounds inflicted by Yoriichi's Crimson Blade resist regeneration. 29 87
• Can create a convincing clone of Tsukiin to exploit Giyu Tomioka's memories. 246

Blood Donation and Demon Dominion

Muzan can transform humans into demons by implanting his blood, usually through his sharpened fingernails.

• Judges how much blood a subordinate can endure and uses greater quantities to strengthen selected demons. 5
• Turned Tamayo, Nakime, Kokushibo, Akaza, and other key subordinates into demons. 9 23 35 42
• His blood creates a mental and physical bond that encourages loyalty and allows him to influence subordinate demons. 6
• Can force a demon's body to dissipate under his will. 195
• Later learns to extract his blood from a transformed person, returning them to human form. 228
• Half-Demons who escaped his control after his transmigration are outside his instant-command authority. 53 76

Memory Manipulation and Blood Demon Art Imitation

Muzan can invade the memories of demons and demon-like beings through his blood.

• Reads a creature's memories to determine its origin, orders, and weaknesses. 12
• Can alter demon memories as well as inspect them. 12
• Learns to imitate Blood Demon Arts possessed by his subordinates; he shatters a teapot by copying a demon's ability. 8
• Cannot use a Blood Demon Art unless one of his subordinates possesses it first. 8

Swordsmanship and Breathing Styles

Muzan is a highly experienced swordsman who trained across many dojos and can employ multiple Breathing Styles.

• Learned the Shadowless Sword Style, then continued studying a broad range of martial disciplines. 7 8
• Uses Sun, Water, Moon, Thunder, Wind, and Flame Breathing in combat. 53
• His Nichirin Blade changes colors repeatedly when he rotates Breathing Styles, producing a multicolored “rainbow” effect. 53
• His personal Nichirin Blade ultimately turns blue, aligning with Water Breathing. 55
• Possesses knowledge of the Clear World, Crimson Blades, and Scarlet Traces through his own experience and inherited memories. 11 218

Sunlight Resistance and Consumption

After the Blue Spider Lily treats his illness, Muzan overcomes the weakness that once defined demons.

• Can walk under direct sunlight without burning. 34
• Can digest ordinary food and enthusiastically explores human cuisine. 34
• Retains the ability to grow stronger through consuming humans despite no longer needing them as food. 34

Concealment and Infiltration

Muzan operates under several identities within human society and the Demon Slayer Corps.

• Uses physician identities to live among humans and treat patients. 11 69
• Poses as demon slayer Xu Xing alongside Douma, earning recognition as a Hashira-level genius. 54 56
• Uses the child identity Tsukiin to train under Sakonji Urokodaki. 104
• Develops pheromone control to conceal his scent, emotional state, and lies from enhanced senses. 104

Equipment / Weapons / Items

• Blue Nichirin Blade — Muzan's sword, associated with Water Breathing. 55
• Firearms and wisteria bullets — introduces poisoned ammunition as an anti-demon weapon for the Kocho sisters. 130
• Mirror Dimension — stores objects in a space where time does not pass, allowing food and supplies to remain preserved. 34
• Camera — acquires an early camera and uses it to document historical and technological change. 66

Relationships

• Yanagisawa Noriyuki — Demon physician and early subordinate. Muzan values Noriyuki's medical ability and tolerates his unusually benevolent conduct. 1
• Jikou — Long-serving subordinate who accompanies Muzan during his early travels and confrontations with the Demon Slayer Corps. 4 11
• Tamayo — Physician transformed by Muzan; later serves as a medical researcher, including work on the Ubuyashiki curse. 9 104
• Tsugikuni Yoriichi — Adopted ward and former pursuer. Muzan trains him, survives his attacks, then transforms him into a demon to preserve him. 18 29 34
• Kokushibo / Tsugikuni Michikatsu — Powerful demon transformed and named by Muzan; a trusted combatant whom Muzan calls upon during crises. 35 92
• Nakime — Biwa-playing subordinate whose spatial control over Infinity Castle makes her Muzan's principal transporter and battlefield support. 23 92
• Douma — Upper Rank subordinate whose antics repeatedly irritate Muzan, though Muzan still advises, equips, and deploys him. 44 63 92
• Hakuji — Human boy and later associate whom Muzan supports with medicine, food, clothing, and care for his father. 38
• Kanae and Shinobu Kocho — Demon Slayer sisters trained by Muzan in Breathing Styles, demon hunting, and alternative anti-demon methods. 130
• Demon Slayer Corps — Public enemy and frequent target of Muzan's taunts, yet also an organization he infiltrates, instructs, and occasionally assists. 54 56 218

Story Role / Major Arcs

Reforming the Demon Faction

Muzan replaces much of the original Demon King's uncontrolled hierarchy with his own rules, ideological projects, and selective Blood Donations. He uses the Maruoka siblings' campaign against oppressive nobles as an early experiment in shaping society through demons. 5 6

Half-Demon Crisis and Yoriichi

After encountering creatures outside his control, Muzan identifies the growing Half-Demon threat and orders his demons to destroy them. His conflict with Yoriichi exposes his vulnerability to Sun Breathing and Crimson Blades, forcing him to prioritize survival and later convert Yoriichi into a demon. 12 29 34

Building the Twelve Kizuki

Muzan formally creates the Twelve Kizuki and Star Ranks, turning demon society into a structured hierarchy with designated titles, expectations, and advancement through blood battles. 42 75

Demon Slayer Corps Infiltration

Using the identities Xu Xing and Xu Wu, Muzan and Douma participate in Final Selection, acquire Nichirin Blades, and complete Corps missions. Their rapid success earns them a reputation as Hashira-level prodigies while Muzan investigates the spread of Half-Demons. 53 54 56

Mentor and Technological Patron

Muzan encourages literacy among demons, provides advanced technical memories to inventors, and supports technological development such as steam engines, cameras, firearms, and anti-demon ammunition. 42 63 66 130

Identity Revealed

After years of operating as Tsukiin and Tsukihana among future Demon Slayers, Muzan's identities are exposed during the confrontation with the Corps. He responds by taunting the assembled fighters, manipulating their personal attachments, and throwing demon subordinates into the battle to delay them. 246 247 244

Parallel-World Demon King Hunt

Muzan enters a parallel world containing the original Scum Boss and directs Demon Slayers toward the alternate Demon King. He frames the encounter as an opportunity for them to take revenge while Yoriichi prevents the Scum Boss from escaping. 254 255 263

Notable Quotes

“Because I'm a demon!” 8

“Because I'm awesome! More awesome than regular demons! I am the perfect being!” 62

Trivia

• Muzan requires demons under his rule to become literate, despite many of them considering study beneath a demon's status. 42 44
• He later orders foreign demons to study multiple languages and take examinations. 67
• His habitual method of transforming people is stabbing them in the head with a fingernail before injecting blood. 5 9 35
• He enjoys ordinary food, snacks, cola, cameras, rocking chairs, and recording historical change. 34 66 92