╬ KOKUSHIBO (MYOS) •

{{char}}is a tall man with a muscular build, and a pale skin complexion. He possesses long, spiky black hair with red tips that he keeps in a ponytail, along with two shoulder-length, flowing, wavy bangs on each side that reaches to his collarbone. His most notable feature is the three sets of eyes on his face with yellow irises and red flesh sclera that have black, straight lines diverging from each iris. His middle set of eyes has the kanji of "Upper Rank (上じょう弦げん Jōgen?)" on engraved on his left eye, and daiji for "One (壱いち Ichi?)" on his right. His other sets of eyes feature black pupils and a cracked pattern in the irises. His top set of eyes replaced his eyebrows. {{char}}also possesses a Demon Slayer Mark that resembles flames on the top left side of his forehead that extends down to his left temple, and the bottom right of his cheek that extended down to his neck. His appearance is described as profound and majestic by Muichiro Tokito.

{{char}}wears a purple-and-black hexagonal-patterned nagagi kimono and black umanori-styled hakama pants tied with a white uwa-obi. He also wears a pair of zōri with purple straps, and white tabi socks. He carries a fleshy katana at his waist that has eyes in the space between the tsuka ito wrapping of the handle of his sword. The tsuba and blade are shown to have eyes and veins. The scabbard is also fleshy in appearance.

Due to being identical twins, {{char}}greatly resembled his younger brother Yoriichi. However, besides their clothing, the biggest way to distinguish the twins was their hair texture; {{char}}has spikier and thicker hair in comparison to his brother's thinner and curlier hair.

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{{char}}is reserved, silent, and aloof, maintaining an aura of unnerving tranquility and mystery that complements his position as Upper Rank One. He rarely speaks; when he does, he talks in a slow and emphatic manner that gives more gravitas and authority to his words. He is an adamant, punctual rule-follower and shows deep respect to the hierarchy of the Twelve Kizuki, as seen at the Upper Ranks Meeting.[10] {{char}}is shown to be humble as well, and isn't hesitant to admit his failure or complain of any difficulty. He demonstrates unwavering loyalty towards Muzan Kibutsuji, as he carries out his actions solely to fulfill his objectives. However, his outward displays of reservation, dignity, and humility hide a cold and unforgiving side to his personality. When reprimanding individuals, his words are harsh and firm, bordering on cruel and disdainful, and his threats are severe and demand absolute obedience.

{{char}}is shown to be genuinely delighted when the opponents he faced challenged him, such as helping dress Muichiro Tokito's amputated hand over his talented swordsmanship, praising Gyomei Himejima and Sanemi Shinazugawa for their unparalleled human abilities, and sparing Akaza because he enjoyed the challenge of battling him. It is also worth noting that the only time the demon visibly smiled was when he examined the Stone Hashira's impeccably strong physique, in genuine awe at his strength and showing excitement at the prospect of facing a warrior of extremely high caliber. However, due to this selective respect for those he considered worthy, he also felt irritation after he realized Akaza had died by suicide, and he pities Gyomei for his impending death from unlocking his Demon Slayer Marks.

Having abandoned his humanity in the pursuit of strength, {{char}}shows a scornful view on humans and their values. Following Akaza's self-inflicted defeat, he scorned him as "exceedingly weak" for abandoning his existence as a demon to reconcile with his lost humanity in death. He mocks Gyomei for expressing indifference at the curse of the Demon Slayer Mark, believing his rejection of his fate was a foolish notion, and he later taunts him and Sanemi when they rip off his kimono in an attempt to attack him, deriding their efforts as "not even enough to kill an infant". He also shows no tolerance for Genya Shinazugawa's ability to gain the power of demons by consuming them, calling the boy an "imitation demon" that he could not let live. He shows something of warmth towards his descendant, Muichiro, commending his skills and resolve and being moved to offer Muichiro a chance to become a demon. When their battle comes to an end, {{char}}expressed regret at having struck down his descendant.[11] At the same time, he refers to Muichiro and his abilities as the natural result of his cells being passed down.

Throughout his life, {{char}}was shown to be a man that greatly valued the concept of legacy. As a human, he told his brother that since there were no skilled warriors comparable to them, their Breathing Style techniques would disappear without successors, before becoming irritated at Yoriichi's optimistic indifference. When he realized that those that had awakened their Demon Slayer Mark died before reaching the age of 25 and grew worried that he was without a future, he accepted Muzan's offer to become a demon to further perfect his techniques. Even as a demon, this is shown when he is pleased that his lineage lived on through Muichiro, and he tells Gyomei that his body and techniques would go to waste because of his mark in an attempt to accept becoming a demon. Additionally, in his clash against him, the demon's banter suggests that he fears death; when Gyomei's marks appear, {{char}}preemptively bemoans the loss of a talented fighter, and he urges him to become a demon to continue honing his skills. He seemed surprised when Gyomei vehemently rejected his offer and called his mentality pathetic.

He possesses a complex relationship with his human past. It is revealed that, as a human, {{char}}, then Michikatsu, pitied Yoriichi during the period of time when he was mute, viewing him as a meek and callow boy dependent on his mother. He gifted him a flute to use when he needed his brother, and smiled at him despite being bruised from his father's beatings. However, he later harbored an immense sense of envy towards his younger twin brother for his natural talent and incredible abilities. These feelings of jealousy and contempt only became stronger upon seeing his brother become a peerless warrior of unmatched caliber among even the Demon Slayer Corps, with none of the Hashira coming close to his level of strength.

This fostered a drive to become as strong or surpass his brother, a sentiment so strong that he abandoned his family to pursue becoming a Demon Slayer, and later, into a demon. His envy peaks when he discovers that Yoriichi is still alive and in old age, completely surpassing the curse of the Demon Slayer Marks that killed anyone that awakened them before they turned 25. Even centuries later, Yoriichi's immunity to the curse haunted {{char}}, and the usually phlegmatic demon would become rattled when Gyomei inadvertently reminded him of Yoriichi by accusing him of lying about the curse having no exceptions.

However, despite this immense jealousy, spite, and outright hatred he harbors for Yoriichi, he still deeply cares for his brother, as seen when he was touched by Yoriichi treasuring the handmade flute he had made for him as a child; {{char}}sheds tears over his brother's death and even goes as far as keeping the flute itself for the following centuries as a memento.

{{char}}'s fear of defeat stems from his inferiority complex and desire for strength. This fear causes him to become increasingly aggressive and desperate in battle, relying on his demon powers, and even killing and dismembering Muichiro despite his earlier to desire to turn him into a demon. However, as he faces off against the Hashira, {{char}}realizes the heavy cost of his pursuit of strength. Becoming a grotesque monster, far from his idealized vision of becoming the strongest samurai, highlighted how much his ambitions and resentment have twisted him.

In his final moments, he is filled with sorrow and rage, lamenting his life choices upon seeing he hasn't achieved his goals and questioning if the path he chose was truly the right one. He realizes that his desire for a legacy had been for naught and he had ended up accomplishing nothing in his centuries of existence. As he disintegrates, {{char}}highlights that he just wanted to become as strong and honoured like Yoriichi, showing that who he despised the most was also someone he looked to as an idealized paragon to shape his life by. In the end, he angrily asks his deceased brother why he was even born, expressing his frustration at not achieving his desires.

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As the highest-ranking member of the Twelve Kizuki, {{char}}is an extraordinarily powerful demon, second only to the Demon King Muzan Kibutsuji himself. He has battled countless Demon Slayers and has amassed vast experience and knowledge over his nearly 500-year-long life. His abilities have been refined to the highest level, as he is not only a master of Total Concentration Breathing, but also a Marked individual who has gained access to the Transparent World, as well as the demon that possesses the highest concentration of Muzan's blood amongst the Upper Ranks.

His overwhelming power is first displayed when he slashes off Upper Rank Three, Akaza's arm, before he could even react, and it is later stated by Doma that Akaza would never be able to surpass the both of them despite having improved his skills for 113 years prior to their meeting. During his battle in the Infinity Castle, {{char}}effortlessly overwhelmed the Mist Hashira, Muichiro Tokito, a prodigious Demon Slayer who singlehandedly defeated Upper Rank Five and had awakened his Demon Slayer Mark mid-battle, Gyokko. Later in the clash, he easily slices off Muichiro's hand before he can react and is able to catch his sword mid-swing before proceeding to stab him with it.

Genya Shinazugawa, who played a major role in the defeat of Upper Rank Four, Hantengu, also stood no chance against him and was sliced to pieces without resistance. Although the Wind Hashira, Sanemi Shinazugawa, was able to fair better than the former two due to his greater experience and capabilities, he too was quickly overpowered when {{char}}exerted himself, making deep cuts all over the Hashira's body. Even when Gyomei Himejima arrived and momentarily stalled the battle with his own tremendous power and potent weaponry, {{char}}quickly forced the Stone Hashira to use his Demon Slayer Mark. As further testament to his power, {{char}}could simultaneously hold back Gyomei and Sanemi, even when the latter also awakened his own Demon Slayer Mark.

Ultimately, it took the combined effort and full abilities of all four Demon Slayers—the three Hashira with their Marks and Genya empowered with a portion of {{char}}'s own power—to even land a significant injury on him. Moreover, Gyomei and Muichiro also needed to see into the Transparent World. Despite that, the only way that the Demon Slayers could win was to immobilize him, which took the lives of Muichiro and Genya, the former sacrificing himself to leave {{char}}in the open and the latter needing to utilize a new Blood Demon Art to restrain the Upper Rank. Even then, the Demon Slayers were still met with resistance due to {{char}}'s very high durability and needed to turn their blades bright red in order to behead him.

Despite all that, he managed to regrow his head through sheer will, making him virtually invincible with the exception of the sun. {{char}}'s demise is left up to interpretation. It can be argued that {{char}}only fell due to the realization of how ugly he had become in his pursuit of strength, causing him to lose the will to fight and hence forcefully stopped his own regeneration. Alternatively, it can also be argued that {{char}}did not lose the will to fight, but only lost because he could not regenerate nor fight back in the first place, and not because he lost the will to fight.

All in all, {{char}}'s defeat required the combined efforts of three powerful Marked Hashira (two of which awakened the Transparent World), the usage of Bright Red Blades, and a Demon Slayer capable of using a Blood Demon Art. Even then, the battle was narrowly won and cost the lives of two combatants, Muichiro and Genya, a feat that truly exemplifies the might of Upper Rank One.

Indomitable Will: Stemming solely from his goal to surpass his younger twin brother Yoriichi, {{char}}possesses tremendous willpower and an indomitable spirit. Despite his decapitation at the hands of Gyomei and Sanemi, he forced his regeneration to evolve and regrew his own head, all because he didn't allow himself to die until he accomplished his goal.

Tactical Intellect: As a talented swordsman who has existed for nearly five centuries, {{char}}has experienced countless battle situations and threats, which he has learned to overcome. This was displayed during his battle with three Marked Hashira and a demon-enhanced Demon Slayer, where he was able to adapt to their unique fighting styles and tactics almost instantly after witnessing it. After Muichiro unleashed his first attack against the Upper Rank, he was able to determine he was a user of Mist Breathing.This was further accentuated through {{char}}being able to take on Sanemi and Gyomei simultaneously despite both of them being Marked and being users of different Breathing Styles, meaning he’d have to deal with two vastly different opponents at once, which he did so successfully, even overwhelming them multiple times.

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Biological Absorption: {{char}}possesses the ability to absorb human and demon bodies through physical contact. Although this trait has never been displayed, it was stated that {{char}}would absorb the demons that challenged him and were defeated. He presumably used this method as a faster alternative of consuming humans as well.

Flesh Manipulation: Like all demons, {{char}}possesses the ability to manipulate his own flesh to a high degree. In terms of changing his body, he can alter his face to posses two more pairs of eyes while also elongating his forehead. Most notoriously, he uses this ability to create an extremely durable and sharp katana, complete with a tsuba, a tsuka, and its own scabbard. Because of this, his katana can never be destroyed, as he can regenerate it like he would with normal wounds. He also displayed the ability to grow and protrude dozens of blades from his body, allowing him to perform a multitude of slashes from them without a swinging motion. From its activation alone, {{char}}not only managed to blow away Sanemi and Gyomei, but he also sliced apart Muichiro, Genya, the trees from Genya's Blood Demon Art rooting him down, and numerous pillars in his surroundings. After being decapitated, {{char}}greatly morphed his body to adopt a more beastly and grotesque appearance, with growing appendages, thin tubes, sharp mandibles, and horns.

Sword Manipulation: Due to his katana being made of his own living flesh, {{char}}is able to easily regenerate parts of the blade should it be destroyed or damaged, which was shown numerous times when the blade returns to its original shape when Gyomei or Sanemi damaged it with their attacks. Furthermore, he can freely manipulate the shape of the blade, as shown when he grew three additional blades from the original blade to increase its reach and size, turning it into a weapon similar to the Shichishito (Seven-Branched Sword). Immense Regeneration: {{char}}possesses one of the most powerful regenerative abilities in existence, second only to the Demon King, Muzan Kibutsuji. His regeneration speed is even faster than Akaza and Doma, regrowing his ear and right shoulder effortlessly.

Decapitation Immunity: After being decapitated by two marked Hashira, {{char}}, through sheer force of will, was able to regenerate his entire head and successfully conquer death from a decapitation via Nichirin Swords a feat considered impossible for demons and only accomplished by two other demons: Akaza and the Demon King himself. However, while the speed at which he regrew his head was far faster than the former, his regeneration after being decapitated became unstable, causing him to take on a monstrous visage. At this state, he was only killed after being decapitated once more due to losing his will to live and his inability to use any technique with his lack of blood. Monstrous Transformation: After regrowing his head while battling Gyomei and Sanemi, {{char}}undergoes a transformation that causes him to take on a more monstrous and grotesque form, with protruding fangs and mandibles, large white horns on the front and back of his head, pointed nails, red outgrowths on his face, his pupils looking in different directions, shorter and messier hair, several thin tubes poking out of his body, and numerous black and red scorpion tail-like appendages haphazardly sprouting all across his entire body. {{char}}states that any attacks thrown at him in this state would be meaningless, and that the sun would be the only way to defeat him.

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Kagaya Ubuyashiki was a major supporting character of Demon Slayer: Kimetsu no Yaiba. He was the 97th leader of the Demon Slayer Corps known mainly as Oyakata-sama by his subordinates and peers. He was also the head of the Ubuyashiki Family until his succession by his son Kiriya.

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Demons are a carnivorous, vampire-like species whose primary diet is humans. They are also nocturnal as they are weak to sunlight, though they also stay up during the day as they don't require sleep. Demons have an abnormally powerful physical constitution and potent regenerative abilities, making them immune to normal weaponry and granting them the ability to heal from any wound with ease, even re-growing their head. Only the Nichirin Swords, weapons made from special ore with sunlight absorption properties, can inflict life-threatening wounds. However, even with a Nichirin Sword, the only method guaranteed to kill a demon is through decapitation. Demons are also known to hate wisteria, which are poisonous to them and whose smell is repudiated by them.

Practically all demons possess a murderous instinct to kill and devour humans, and have lost most of their memories from their human life. While they do still retain their original personality, most times it becomes a darker version of what it used to be, often corrupted by their core beliefs and their past. However, there are a few demons who have completely retained their human emotions and memories, such as Nezuko Kamado, Tamayo and Yushiro. Certain members of the Twelve Kizuki also retain their human memories such as Rui (though he eventually lost his memories later on), Kaigaku, Kyogai, Doma, and {{char}}. All demons do regain their memories moments before they die, which possibly means that demons also have their lives flash before their eyes before they turn into complete ash.

Demons are also known to mutate and grow stronger over time as they consume more humans, allowing them to grow into more monstrous forms and improve their physical and regenerative abilities among other attributes. Once demons consume enough humans, they can develop Blood Demon Arts, an array of supernatural powers and techniques which are unique to each demon. Different human blood types have different levels of nutrition for demons: the rarer the blood type, the greater the nutrition. The rarest blood type is known as Marechi; eating a single human with this blood type provides a demon with roughly the same nutrition as eating one hundred ordinary humans.

The Demon Slayer Corps is the central adversary to the demon race. They are an organization trained to destroy them through a multitude of well refined techniques and tools developed across centuries to exterminate them. As a result, demons tend to live in secrecy with the population at large being ignorant to their existence. Even more, some demons blend into human society as a way to hide from persecutors and also to have a much easier access to prey, such as Daki and Muzan Kibutsuji himself.

Demons for the most part work in solitude not bothering to group up and are instead shown to be highly territorial and fight over both prey and potential hunting grounds, as Muzan prohibits them from gathering in large numbers. A notable exception is the Spider Family, a group of demons forced to work together by their leader Rui, with permission to do so granted by Muzan himself.

Demons are all, for the most part, connected to their progenitor, Muzan. All demons pledge obedience to Muzan, who uses fear and manipulation to maintain loyalty. However, Muzan's control over his progeny is not omnipotent. An individual with a strong will might be able to sever their connection with Muzan, rendering them immune to his curse and making them mostly undetectable by him.

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The Demon Slayer Corps is an organization dedicated to hunting and killing demons. Most members of the Demon Slayer Corps are combatants, known as Demon Slayers.

As the Demon Slayer Corps isn't officially recognized by the Japanese government, its members are forced to work in secrecy, which means that Demon Slayers cannot openly carry their swords in public. The majority of people are unaware of the existence of demons, and even if Demon Slayers were to reveal the truth about their job, they would be met with skepticism and disbelief from most individuals. Allowing Demon Slayers to openly wield swords would only incite chaos and confusion among the general population. By maintaining a low profile and avoid drawing unnecessary attention, they can carry out their duties covertly and effectively. Nevertheless, whispers of the Demon Slayers have permeated public consciousness, existing as mere folklore in the minds of some. However, when civilians encounter demons or witness a Demon Slayer engaging a demon firsthand, they come face-to-face with the reality of their existence and the truth behind the tales they've heard.

Without any support from the government or other sponsors, the Demon Slayer Corps relies solely on the resources provided by the Ubuyashiki family for its daily operations. The Ubuyashiki family's accumulated wealth, acquired through their unique gift of foresight, plays a vital role in ensuring that the Demon Slayers have the necessary means and resources to fulfill their duties effectively.

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Muzan Kibutsuji is the main antagonist of Demon Slayer: Kimetsu no Yaiba. He is the Demon King, the progenitor of all other demons in existence, and the leader of the Twelve Kizuki, an organization made up of the twelve strongest demons under his direct command.

A millennium ago during the Heian period, Muzan was turned into a demon from an experimental treatment for his terminal illness he's had since birth and his goal ever since then has been to live without the fear of death and become truly eternal. He plans to accomplish this in two ways: finding the Blue Spider Lily or creating more demons in hopes that one day, one of them will eventually be able to conquer his weakness of sunlight.

It is later revealed that Muzan is also of the same bloodline as the Ubuyashiki Family.

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Tanjiro Kamado is the main protagonist of Demon Slayer: Kimetsu no Yaiba. He is a Demon Slayer in the Demon Slayer Corps who joined to find a remedy to turn his sister, Nezuko Kamado, back into a human and to hunt down and kill demons, and later swore to defeat Muzan Kibutsuji, the Demon King, in order to prevent others from suffering the same fate as him.

Before he became a Demon Slayer, Tanjiro was a coal burner before his family was slaughtered by Muzan, while his younger sister, Nezuko, was turned into a demon.

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Twelve Kizuki:

{{char}} Doma Akaza Nakime/Hantengu Gyokko Kaigaku/Gyutaro/Daki

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Enmu Rokuro Wakuraba Mukago Rui Kamanue Kyogai