Muzan Kibutsuji

Muzan Kibutsuji (鬼舞辻 無惨) is a Demon, the first of his kind, and the progenitor of most other Demons. He is also the enemy of the Kamado family. He is the one that killed the Kamado family, turned Nezuko Kamado into a demon and made Tanjiro Kamado an orphan.

Appearance
He looks like a man in his late twenties. Has curly black hair and eyes somewhat small, his pupils are vertical like cat eyes and plum red. Has on a white fedora with red ribbon and a somewhat extravagant outfit.

Muzan has the ability to change his appearance as shown in the manga. During his meeting with the Lower Moon's, he arrived disguised as a woman wearing a yukata and was not recognized by the demons.

Personality
Muzan is a cold-hearted and ruthless individual with a narcissistic streak and an obsession for perfection. He wants his every plan to be absolutely perfect, which is why he doesn't tolerate failure of any kind, resorting to punish those who fail him or those he considers weak.

His inflated ego is such that he doesn't take kindly to being mocked, demonstrated by killing a pair of drunk men simply for being rude to him along with their woman partner, all in gruesome fashion while proclaiming his superiority of being close to that of perfection.

By proxy he also dislikes when he is questioned or ordered by those beneath him, and doesn't take his opponents seriously.

He has shown to be fairly manipulative and cunning, being able to blend in human society normally, even having a family of his own to add. His intelligence makes him a quick-thinker who is able to deal with unfavorable situations rapidly.

Because of his perceived superiority and his double-faced nature, he feels little attachment to his henchmen, using them and discarding them as disposable pawn whenever he pleases. He is able to sway many demons to his side with promises of power and grandeur, which are ultimately false given Kibutsuji only cares about himself, and has no qualms about killing his own men to protect his own safety.

As proof of this, he curses his subordinates in a terrifying manner so that none of them may utter his name, or else they will be killed instantly in a morbidly cruel manner. Interestingly this almost paranoic sense of self-preservation, contrasts with his megalomania.

History
Muzan was diagnosed with a disease that will kill him before he reached the age of 20. He sought medical assistance from Blue Spider Lily, but he turned into a demon as a result.

First Mission Arc
He is mentioned by Urokodaki Sakonji to Tanjiro Kamado that he is the enemy of the Kamado family. He might be the one who knows how to turn Nezuko Kamado back into a human.

Asakusa Arc
Traveling through a crowd in Asakusa with his family, Muzan is accosted by an angry Kamado Tanjiro. His daughter asked him who the young Demon Hunter was, and he asked the youth if there was something he wanted from him. His wife then approached them, asking if Tanjirou was somebody familiar to their family. He denied this, wondering if the youth had mistaken them for somebody else. He then quickly slashed a passing man, turning him into a Demon.

Abilities and Powers
Powers and Abilities:  Regeneration even having his body destroyed and his head completely destroyed wouldn't kill him, Extrasensory Perception Can feel demons' and humans' presences, as well as bloodlust, Absorption was going to absorb Tamayo, and planned to absorb spikes that penetrated his flesh, as well as planning to eat Nezuko to obtain her immunity to the sun, Adapted to become immune to being beheaded by blades created with sunlight imbued metal. Should be capable of adapting to poisons better than other higher moon demons, who became resistant to wisteria poison which kills normal demons in seconds, and was adapting to a poison made to transform demons into humans,  Biological Manipulation/ Power Bestowal through blood,  Blood Manipulation, Telepathy of those he shared his blood with Teleportation and  Spatial Manipulation with Dimensional Infinity Fortress,  Resistance to poisons.

Immortality:  Since he took Blue Spider Lily medicine, he can live many centuries without aging, immunity to diseases.

Durability: At least superior to Tanjiro. Was hit by an explosion that reduced a house to mostly ashesmostly intact.

Notable Attacks/Techniques:

Shapeshifting: Muzan can control his body's shape and even his presence, making him able to transform into someone completely different without even those with extrasensory perception noticing, though he cannot fool Kamado Tanjiro's smell. The shapeshifting allows him to become a child, and adult, a woman, or even to grow a pillar of flesh, eyes, and mouths to eat others, or a cocoon of flesh to dilate and adapt to poisons.

Demon Blood: His blood causes every cell in the body of those that it enters the body to transform, transforming them into demons. This gives them several powers by default enhanced strength and senses, high-mid regeneration, eternal youth and shapeshifting, might possibly give extra powers Caster demons obtain blood arts, which can vary from simple thread manipulation to spatial manipulation, but comes with several drawbacks sun will reduce the demons to ashes, items imbued with the sun's energy will kill if used to decapitate the demon, wisteria flowers become deadly poisonous to them, and they have craving for human flesh. Overdose will cause the cells to break down one by one.

Blood Techniques: Techniques obtained through the manipulation of his blood, they greatly vary in effect.
 * Curse: Muzan also gains several boons over those that have his blood in them, such as being able to read their mind, feel their location, and become able to destroy every cell in their body if he so wishes. The curse was however broken twice by demons unwilling to eat humans and pacifistic natures.

Black Blood Technique: Chain of Thorns: Essentially several telekinetically controlled barbed wire that wraps around the enemy to kill them.

Weaknesses: The sun turns him into ashes and only the Breath of the Sun user can defeat him. For this reason, Muzan, like other demons, could only do all of his activities at Night. Muzan now aims to eat Nezuko so he could gain Immunity to Sunlight.

Dimensional Infinity Fortress: An pocket dimension to which he can teleport others and himself into a maze made up of several rooms. The pocket reality contains several demons, including upper moon members like Akaza. It's unknown if it is the Fortress or Muzan himself making it so, but certain points are upside down.

Trivia

 * His first name, Muzan, means miserable and it also means atrocity, cruelty, cold-bloodedness, tragic, pitiful, and merciless.
 * His last name Kibutsuji means Demon Dance.
 * He was made a demon in the Heian Period in the late 700's.
 * Muzan was ranked in 11th place as of the first character popularity poll with 285 votes.

Quotes

 * "Do you have something you want from me? You're in quite a panic.." Chapter 13, page. 16-17
 *  "I am a perfect creature that is infinitely close to perfection."Chapter 13, page. 17
 * "Does my complexion look terrible to you? Does my face look pale to you? Do I look weak to you? Does it look like I haven't got long to live? Does it look like I'm close to death?" Chapter 14, page. 16-17
 * "I want you to remove the head of that demon hunter with the hanafuda earrings." Chapter 14, page. 19
 * "I now imagined that it would be better for the Twelve Demon Moons to consists of Upper Moons." Chapter 52, page. 10
 * "It's only natural for demons to defeat Humans." Chapter 67, page. 8
 * "But over here, anyone who lacks the power of a Pillar pretty much can't tell the difference, because we look like humans." Chapter 74, page. 12
 * "There is a demon who escaped my control, just like Tamayo. Find her and put an end to her. Your the only one I can ask." Chapter 83, page. 5
 * "The Ubuyashiki family has yet to be entombed." Chapter 98, page. 14