Tamayo

Tanjiro sensing Tamayo's pure intentions. Tamayo is a gentle, wise, and incredibly intelligent individual. Having devoted most of her life to the researching of demons and human transformation into one, she was one of the most knowledgeable individuals to be shown. Despite the generally antagonistic and virulent relationship between humanity and demons, she shows a great deal of kindness towards humans. She made it a part of her mission to assist injured or sick individuals with her expansive medical knowledge - Tanjiro Kamado being among them. Tamayo had a strong preference against violence: instead of killing humans for their blood, she chose to buy blood from consenting donors to survive. She was adamant in teaching her assistant, Yushiro, against violence and often reprimanded him for his habit of hitting others. She was one of the few demons who, after her transformation into one, was able to regain and retain her human emotions. thumb|Tamayo's viciousness towards Muzan. However, despite her usual kind, caring, and considerate disposition and personality, Tamayo has displayed a more cruel and vicious persona upon confronting Muzan. This was seen when she gleefully boasted to him that she had successfully created a human-transforming drug and managed to inject it into him, and later, upon being devoured and eaten, reduced to mere cells inside his body, Tamayo again showed her cruel side as she revealed the real effects of her drugs. Muzan hinted that this vicious personality was Tamayo's original personality back in her earlier years as a demon, though his antagonistic association with her makes this dubious. It is possible that Tamayo's stark change in demeanor is only triggered when being with Muzan due to the great hatred she bore of him. During her time as a servant of Muzan and prior to meeting Yoriichi Tsugikuni, Tamayo was shown to have a more docile personality, likely a result of her realizing how impossible it was to defeat Muzan with her power to avenge her family. However, this changed upon her witnessing Yoriichi's strength and how close he came to killing Muzan, as Yoriichi noted that he saw a glint of hope in her once-deadpan eyes as she realized that he'd almost killed her former master, showing that, upon seeing Yoriichi's power, Tamayo's resolve to avenge her family was reignited. Tamayo's anger towards Muzan for tricking her into undergoing a transformation. Tamayo hated her identity as a demon: when she was first encountered by Tanjiro and he had deduced that it was her Blood Demon Art that assisted him, she mentioned that she could still be called a human. Upon learning that Nezuko had recognized her as a human and hugged her after helping defeat Susamaru, Tamayo pulled her in closer and tearfully thanked Nezuko Kamado. During her skirmish with Muzan to inject her drug into him, Tamayo declared that she had no intentions of being a demon and simply wanted to survive her illness and be with her family, showing that Muzan had tricked her into undergoing a transformation without speaking of the consequences. The accidental murder of her beloved husband and children burdened Tamayo with lifelong sorrow and regrets, so much she sought death to atone for her sins.

Tamayo is a petite young woman with long, dark brown hair, parted in the center and worn braided back into a large, low bun, which is held in place by a floral tama-kanzashi hairpin. She has large, gentle eyes that initially do not possess pupils, only a haze of lavender that fades to dark purple the higher it goes, and notably red lips in contrast to her pale complexion. She also possesses sharp, polished fingernails. She is noted to have an attractive appearance by Tanjiro and Yushiro. Tamayo wore a dark purple medium-lengthed hōmongi kimono that is decorated with wavy pale purple tree branches and red flowers with green leaves, and a cream-colored taiko musubi obi to secure it around her waist, as well as plain white socks and violet zōri sandals. During the confrontation between the Demon Slayer Corps and Muzan, Tamayo's eyes are shown to have black cat-like pupils and Yushiro's talisman scattered in her kimono. In her past, Tamayo wore her hair tied in a low ponytail.

Overall Abilities
Tamayo casting her Blood Demon Art. As one of the oldest to ever exist, predating the Twelve Kizuki entirely, and armed with unparalleled knowledge regarding the science and physiology of demons, Tamayo is a very powerful demon. She was able to enchant and distract a platoon of police officers, preventing them from seeing herself, Yushiro, and Tanjiro in plain view and later managed to easily lull Susamaru into accidentally saying Muzan's name, despite the extreme fear nearly all demons possess of him, through the use of her Blood Demon Art. However, her greatest weapon is her vast knowledge regarding medicine and the inner workings of demons. She was able to remove the innate curse Muzan Kibutsuji placed in her body through medical means, became only the second demon to ever transform a person into a demon without Muzan's influence, also reversing the transformation of a demon, something that was once thought to be entirely impossible, and played a pivotal role in the eventual death of the Demon King by developing a potent drug that drastically diminished his once unequalled physical abilities. Medical & Pharmaceutical Skills: What Tamayo lacks in combative prowess, she more than compensates with extremely honed skills in the fields of medicine and pharmaceuticals and centuries of experience in medical practice, possessing the skill to alter her own body so she could survive on only a small amount of human blood. She was also able to turn the terminally ill Yushiro into a demon without Muzan's blood. Before the final battle, she turned Chachamaru into a demon as well. She later managed to free the Asakusa Demon of Muzan's influence and regain his consciousness using Nezuko's blood. To further showcase her pharmaceutical skill, Tamayo was also able to assist Insect Hashira Shinobu Kocho in saturating her body with deadly Wisteria poison without it so much as causing her the slightest illness; a tactic the Hashira would later use effectively against Upper Rank Two, Doma. She devoted herself to researching a method to permanently weaken Muzan with a deadly drug which contribute to his death. *Anti-Blood Demon Coagulant: Tamayo created this medicine to prevent a demon's Blood Demon Art from progressing. Yushiro used this medicine to cure Zenitsu Agatsuma after his fight with Kaigaku. Anti-Kibutsuji Drug: It was later revealed that by teaming up with Yushiro and Shinobu, Tamayo had successfully created an extremely powerful, four-stage drug that could gravely weaken Muzan. Once administered into him, its effects would be strong enough to significantly harm him despite his immense physical resistances and abilities. The first stage of the drug consisted of the same human-conversion stage that was included in the drug given to Nezuko. The second stage was developed to accelerate his aging so much, Muzan would have to expend much of his power to stave off its effects. The third stage ensured he was unable to split his body in an attempt to escape. The last and final stage caused the now severely weakened Muzan to deteriorate rapidly, to the point that even the most minor of his wounds would have difficulty healing.