Spider Demon (Daughter) (蜘蛛鬼「姉」 Kumo oni: Ane) was a member of the Spider Family.
Daughter's physical features are very similar to that of her "Younger Brother," Rui. She has the looks of a demon girl in her early teens with a completely pale, milky-white skin complexion, snow white hair, and pure white eyes with only her silvery pupils separating them from her sclera. She also possesses several red, dot-like patterns on her face similar to her "family".
Daughter's original appearance as a demon was completely different than her current, having morphed and changed her features due to being forced by Rui as a condition to be accepted into his family. Her original appearance was that of a teen demon with black hair, slitted cat-like eyes and pale grayish skin.
Daughter is shown to be the most cautious within her "family," having instead opted to observe and stand back rather than jump right into the battle against Demon Slayers. She is also shown to be very cowardly, both with battling against the Demon Slayer Corps and dealing with her family's internal conflict. When her "mother" was being violently abused and reprimanded by Rui and her "father," she stood back and gave her her the same severe glare due to her weakness instead of helping her. She again shows her cowardice by trying to convince Rui to run instead to fight after most of their family was defeated, which enrages him and leads him to wound her.
In truth, Daughter loathes and hates her "family" and began to think that she would have likely done better on her own. She believes that the rest of her family are fools for playing along with Rui, despite him not having any real emotional attachment or care for any of them. She nonetheless did whatever it took to survive and stayed with them, knowing she stood no chance of surviving if she were to try to escape.
She even went as far as attempting to use sympathy and pity on Shinobu Kocho, knowing that she was a Demon Slayer, by pleading that she was forced into her situation by Rui. However, this contradicts her actions as she went through various lengths to stay with him and his family, revealing that she only does what is convenient for her own survival. She later shows herself to be gullible enough to fall for Shinobu's fake sympathy and begin to openly admit her total count of human victims.
Daughter was originally a lone demon who lived on Mount Natagumo. She found herself being pursued by several Demon Slayers and was cornered at an abandoned house in a field. When her assailants were nearly on top of her, they were interrupted by the arrival of Rui, Lower Five of the Twelve Kizuki. He offered a chance to live by asking for her to be a member of his "family" to which she graciously accepted. Rui then quickly dispatched the Demon Slayers and she soon found herself introduced to several spider-like demons living in the house. Rui took her hand and she was accepted as a new sister.
Inside with Rui, she was presented by her new older sister with a beverage to drink, containing a drop of Rui's blood. Immediately after taking it, she found herself in intense pain as the drop of Muzan's blood began to physically change her. Rui then added the "finishing touches" and ripped off her face to make her appear more like him, as she screamed in agony. After her ordeal, she was congratulated for being a true part of the family now.
Though she was initially happy to be safe from Demon Slayers, she came to understand that Rui's view of a family was twisted and strewn with his cruelty. She was told by her sister that they were all strangers who came to Rui for protection, only for him to abuse their need for survival with his own ambitions at making a family. They witness their "mother" being tortured by Rui and Daughter is offered a chance at escaping their situation.
The next day, she and her older sister attempt to descend the mountain but found their path blocked by Rui himself. Daughter, knowing the consequences, quickly re-joined his side and later watched as Rui tortured his sibling and left her to die. Despite going with her plan to escape together, Daughter looks at the horrifically wounded body of her former sibling and walks away without a second thought.
Now more fearful of Rui than ever before, Daughter did her best to live to his expectations and be a "good sister". Knowing that escape was futile and she would be killed for attempting to do so, she became more withdrawn and aloof. During one occasion, she saw her "mother" being tormented by both Rui and her "father" because she repeatedly failed to meet the expectations of her role. Watching the frightened demon beg for mercy, Daughter coldly looks at her without intervening in the situation, in order to remain safe.
Mount Natagumo Arc As they head deeper into the forests of the mountain, Daughter is spotted by Tanjiro Kamado and Inosuke Hashibira only after recently defeating her "mother". She screams her father's help and runs away, leaving him to fight the two Demon Slayers on his own. She meets with Rui and tells him of their mother and and elder brother's demise, asking for his next course of action. While doing so, unbeknownst to Daughter, her eyes changes back to their original appearance and is seen by Rui, who mercilessly slashes her face in his webs, angered that she unwittingly changed her appearance. They are interrupted by the arrival of Tanjiro, having been flung away from the battle by their father. Still on the ground in pain, she hears Tanjiro confront Rui for abusing her, flatly declaring that their bond is fake. This shocks Daughter, as she has never seen anyone stand up to him, much less a human. She watches the two clash and later sees the intervention of Tanjiro's sister Nezuko, taking the hit from Rui's webs to protect him. Shocked to see her emerge from seemingly nowhere, she then looks to Rui, visibly shaking at the sight of sibling love between the two. Knowing what will happen next, she tries to draw his attention and asks he do not forget about her, only for the Lower Rank to slice her to pieces with his threads. While making her way down Mount Natagumo, she comes across Murata in her path and quickly ensnares him in a silk cocoon. She taunts him with the details of how he will die to her cocoon's acid, only to be interrupted by the Insect Hashira. Shocked at her sudden appearance, Daughter hears Shinobu greet her and comment on the full moon tonight. She tries to ensnare her as well in her silk but Shinobu proves too fast and nimble to hit; she eventually knocks the demon to the ground and questions her. Horrified and angered, Daughter tries once more to trap Shinobu in her silk, but the Insect Hashira proves too quick to hit, as she laments their inability to become friends. When she turns to fight her again, she loses sight of her assailant, before looking up and watching Shinobu lunge at her with a flutter of butterflies at her back. They fly past her but Daughter sees one land on her finger; watching with great curiosity, she sees as the butterfly begins to bleed, with her own body bleeding in certain spots as well. Shinobu had used Insect Breathing, Butterfly Dance: Caprice, striking her too quickly to be noticed. Initially, Daughter reaches for her head and feels her neck is still intact, before noticing that Shinobu's blade isn't built to slice off a demon's head. As she declares that Shinobu is someone she can kill, her hand begins to bleed internally and her body convulses. As she begins to vomit blood and her regeneration starts to fail, Daughter lets out one final scream of agony before slumping to the ground, dead from Shinobu's wisteria poison. Overall Abilities: Enhanced with a drop of Muzan's blood from Rui, Daughter proved to be a decently strong demon. She was solely responsible for the greatest loss of life on the mission to Mount Natagumo, having killed at least eighty Demon Slayers through her cocoons. She was quickly able to overwhelm an experienced Demon Slayer, Murata, and would have certainly killed him if it wasn't for Shinobu's intervention. However, she was defeated by the Insect Hashira rather easily. Regeneration: Like all demons, Daughter possesses powerful regeneration, able to heal the numerous severe wounds given by Rui's steel-like threads. She was even able to survived being decapitated and sliced into several pieces by him, with only a short amount of time to heal completely. Despite this, her regeneration was overwhelmed and defeated by Shinobu's advanced wisteria poison. Blood Demon Art Silk Manipulation: Like her "mother" and Rui, Daughter can manipulate threads made from her own cells, this time in a fashion similar to silk that forms a cocoon instead of threads that resemble wires. Despite being extremely soft, her silk is stronger and more durable than metal, even a normal Demon Slayer can't cut or pierce it with a Nichirin Sword. Acid Manipulation: Daughter can manipulate and generate acid made from her own blood and flesh. The acid she creates can easily dissolve a person, though the process is a little slow.
In spite of his initial anger, Rui decides to give her a final chance at redemption, asking that she hunt down the Demon Slayers still on the mountain for him. Unwilling to anger him again, Daughter obeys his commands, picks up her severed head and runs away to heal and do as he wishes. As she regenerates from her wounds, she reminisces on when she first met Rui; how he was the one to protect from the Demon Slayers on the mountain and her initial introduction to her family. She remembers how his high expectations and abuse would cause conflict and pain towards the other members, though she denounces them all as fools for playing his game.
Daughter quickly begs Shinobu for mercy, stating that she would be killed if she disobeyed Rui. Shinobu, seemingly sympathizing with the Demon's plight, says that she will cooperate with the Demon if she answers a few of Shinobu's questions, starting with the number of her victims. Trapped and scared, Daughter answers that she has killed five under orders, only for Shinobu to correct her answer by stating that from the direction she came, she counted eighty cocoons in the trees, with all human captives dead and liquified.
Daughter denies killing so much but the Hashira states that in one area alone, she counted fourteen. Shinobu adds that she isn't angry, only trying to be as accurate as possible. When asked what the point of checking this information is, Shinobu tells the Spider Demon that in order for them to be friends and to satisfy those who have died, she will have to endure punishment, explaining in gruesome detail what she had in mind for this, and adding that since she won't die from it, there will be no aftereffects.Abilities
Fighting Style
Acid Cocoon - The technique works by entangling her target in a web-cocoon filled with acidic fluids which are capable of dissolving the clothes of the victim (even the specially made battle uniforms of the Demon Slayer Corps). The acid will then move on to the target's flesh, making their body soft and ready for her to consume.