Muzan

Muzan has seven hearts and five brains. Regeneration: Muzan can remain alive even if his body and head are completely destroyed. Extrasensory perception: He can sense the presence of other demons or someone's bloodlust. Absorption: The man can absorb other demons or objects. He planned to absorb Tamayo and the thorns that had pierced his body along with her, and then eat Nezuko to gain immunity to the sun. Poison Resistance: His body is much more resistant to poison from wisteria, which is lethal to normal demons and can kill them in seconds.

While Muzan was still in his mother's womb, his heart stopped several times. He was born without a pulse and didn't breathe, leading to him being considered stillborn. He only let out his first cry when they were about to cremate him. When Muzan was a young man, he was diagnosed with a disease that would kill him before he reached 20. The doctor treating him gave him a prototype cure, but Muzan, enraged by his worsening condition, killed his doctor. He later realized the cure had indeed worked, and his body had grown stronger. Eating people to survive was easy for him, but he faced another problem: he couldn't live in the sun. Because sunlight was now lethal, Muzan was forced to become nocturnal, which angered him greatly. At that moment, he deeply regretted killing the doctor before he finished developing the cure, called the "blue spider lily." Muzan searched across the country for the spider lily, an ingredient in the cure, but was unable to find it, prompting him to create more demons. He wanted to spread demons throughout the world, hoping that one of them would eventually be able to defeat the sun, or at least find the blue spider lily, so that Muzan could become a perfect being. Some 400 years before the manga's plot, Muzan encountered Tamayo, who was ill. Muzan transformed her into a demon. During this time, he also met Michikatsu Tsugikuni, a demon slayer who wielded the breath of the moon. Knowing that Michikatsu feared dying at 25, Muzan promised him immortality and incredible power. Michikatsu, who had always envied his younger brother, accepted the offer and became a demon named Kokushibo, serving Muzan as the first upper moon.

Once, a demon hunter, possessing the Breath of the Sun, nearly killed Muzan, but the man survived and henceforth became more cautious around anyone who possessed or could possess this breath. A distinctive feature of these people were hanafuda earrings.

He has proven himself to be quite manipulative and cunning, able to fit comfortably into human society, even having his own family. His long life and constant practice have allowed him to assume many roles in society and play them wisely, including those of children and women, if he so chooses. This life has also given him great intelligence and the ability to think tactically. Muzan is a clever strategist, capable of quickly and effectively handling adverse situations, although this may also be because the loss of subordinates means nothing to him in the long run.

Due to his apparent superiority and two-faced nature, he feels little affection for his minions, using and discarding them as disposable pawns whenever he pleases. He refuses to allow his subordinates to question his will, regularly employing brutal repression. Many of his subordinates, in turn, deeply fear him and carefully guard their words and thoughts, afraid to say anything that might upset him. They dare not even think anything that might be perceived as hostile by Muzan, so able is he to read the minds of all the Moons. He is able to sway many demons to his side with promises of power, revenge, and greatness as long as they serve him. His intellect and manipulation shine here, as many find these promises quite appealing, as he encounters many of his subordinates at their lowest point, when their emotions are easily fed to him. Unfortunately, all of these promises are ultimately false, given that Kibutsuji only cares about himself and has no qualms about killing his own people to protect his own safety.

When he's not hiding behind a facade, his malice and overflowing violent intent are so incredibly vicious that they can be perceived by others. Yoriichi Tsugikuni, in particular, described him as boiling magma erupting from a volcano, ready to devour everything.

Muzan is merciless and strives to bring each of his plans to perfection.

He doesn't forgive the Moons for incompetence and failure, but he can praise them for successfully completing a mission. Kibutsuji doesn't take his enemies seriously. Muzan also doesn't like being questioned or given orders. He tends to be narcissistic. It's also not hard to guess that Rui was one of Muzan's favorites, as he no longer saw any point in keeping all the Lower Moons and killed them all after Muzan's death. There are reasons for this: Rui, unlike other demons, was loyal to Muzan and actively killed demon hunters.

His inflated ego and delusional sense of self-worth are so great that he cannot bear to be mocked or corrected, believing that others exist only to serve him. This also means he rarely takes any opponent or threat seriously. He brutally murdered a pair of drunken men simply for being rude to him, and killed their companion when she did nothing, all while proclaiming his own perfection and superiority over them. When he finally managed to confront Kagaya Ubuyashiki, the man responded to Muzan with a tone of pity and sorrow for the life he had led. In Muzan's mind, these were registered only as insults and threats, which he used to justify his hatred of Humanity and the Demon Slayers.

Furthermore, his delusional sense of omnipotence leads him to compare himself to natural disasters, namely, to things far beyond what a person can compare to and combat. As a result, he believes the Demon Slayers are a group of deviants who are unable to accept the natural order of things and regain normalcy while others simply move on after tragedy. His analogy reveals a complete inability to feel empathy or remorse for his actions.

Muzan appears to be a man in his twenties. He has wavy black hair and red eyes. Muzan dresses very extravagantly and wears a white hat with a red ribbon. In the manga, he is shown to be able to change his appearance.

Muzan has three images in total: the image of a young man, a woman, and a little boy.

Muzan, as a woman, wears a yukata with a floral pattern, his hair is pulled back into a voluminous bun, his face is made up, and his hands have demonic claws.

After he neutralizes Tamayo's poison and emerges from his flesh cocoon, Muzan's hair grows to shoulder length and is dyed a lighter color. He also grows multiple mouths all over his limbs, each lined with a set of incredibly sharp fangs that he can use in combat and for regenerative purposes. His skin also develops a dark red mass, growing from the tips of his limbs and branching out across his body.

Feeling himself dying, he opens his mouth wide to swallow his opponent. In this form, his pupils become narrower and look in different directions.

In sunlight, Muzan changes his form once more, becoming a huge, baby-like creature. In this form, he can easily and quickly chain the earth.