Kiseki Kusanagi (草薙 キセキ Kusanagi Kiseki) is the younger twin sister of Takeru Kusanagi and is one of the last surviving members of the Kusanagi Clan. She is the current host of the Hyakki Yakou, the manifested form of countless demons that is the product of the Kusanagi Clan's inherited curse. For the longest time, she was imprisoned deep inside an Inquisition holding facility where she was both experimented on for her immortality and restrained to keep the world at large safe.
As Takeru's twin, Kiseki has long black hair and brown eyes. Presumably through years of confinement and sleep, she has a small body figure with thin arms and legs. During her years of imprisonment and experimentation she wore a modified white straight-jacket. After her freedom she wore a black and red dress.
Kiseki is extremely strong willed as she continued to remain sane after being killed repeatedly throughout her years in captivity. With Takeru being the only person she's ever interacted with, she is understandably shy and fearful of others. However, she still exhibits inherent kindness to those who treat her like a human being. As she grew older, Kiseki began to feel the immeasurable guilt in how her very existence was responsible for so much death and coupled with her constant, physical torment, her only wish was to be killed.
After Takeru goes back against his word to end her suffering, Kiseki becomes psychotically obsessed with destroying the world in the hopes that Takeru would kill her.
When demons were said to have roamed the earth, the Kusanagi Clan were first and foremost trained in combating them. However, the demon's method of reproduction involved reincarnating from the bodies of humans and were truly unable to be wiped out. The clan came up with a solution with the onmyouji to find a way to end the threat of the demon's forever and devised method was to seal the essence of the demons within the family bloodline and should their traditions not be kept, the demons would be released onto the earth once more. For generations, this "curse" gave all the following males of the Kusanagi clan to hold the bodies of humans while having the souls of demons. In reverse, the women born into the clan were plagued with the monstrous bodies of demons while holding the soul of a human. By tradition, the father of each successful generation was to kill their daughter and this was upheld for hundreds of years. But it was said that each incarnation of the Hyakki Yakou grew stronger with each death. On the day of Kiseki's birth, her fear and will to survive drove the Hyakki Yakou into killing a large number of people.
After her birth, her father attempted to kill her on multiple occasions but he was unable to completely end her life. Instead, he sealed her inside an underground box within a small shrine made of anti-magic material on a mountain deep in the forests. For a number of years, Kiseki was completely deprived of human contact and only encountered Takeru by chance. Takeru began interacting with her and she sought to continue to be with him. This lasted for a month before Takeru was caught by his father when he tried to break open Kiseki's box and was told that Kiseki was his twin sister that he himself was unable to kill her. Takeru was sent away to train but when he came back to his village, Kiseki's loneliness manifested through her awakened powers and devoured the village. In the middle of the massacre, Kiseki begged for Takeru to kill her, the first time she ever wished for him to do so and Takeru was unable to make a decision and hesitated. She was eventually captured by Hayato Kurogane and imprisoned by the Inquisition. Takeru continued to visit Kiseki whenever he had the chance but on a fateful day when he lost to Ouka in the mock-battle test in middle school, his anger and determination had Kiseki yell at him for being incapable of understanding how other people felt.
Hero Summoning Arc Edit
Takeru mentions Kiseki as his primary reason for wanting to be a highly-paid Inquisitor. The epilogue documents one of his visits to Kiseki's holding area.
Hyakki Yakou Arc Edit
Kiseki is fully introduced in Takeru's visit to her where it is revealed that she is usually kept asleep and in complete solitary confinement outside of her visits. Takeru was given 15 minutes, 5 minutes longer than his usual 10, from Sougetsu as a sign of good faith but he declines the extended time. The two converse about his everyday life and Kiseki is rather interested in hearing about the girls her brother has been meeting, especially the one with "sunset colored hair". She congratulates him on finding love but Takeru corrects her, saying that his feelings for her are admiration, and that he sees her as his benefactor. After sharing his stories, Takeru cries at the prospect at how he was still unable to do anything for her other than visit her and tell her stories and vows to give her a normal life. Takeru leaves after his time limit passes up and Kiseki and Takeru share their tearful farewell until their next meeting.
Kiseki's reasons for being in captivity are fully revealed during Sougetsu and Kurogane's inspection on her in the facility's control room where the former reveals her demonic power that manifests through countless masses of flesh, with her at the center, that assimilates anything it touches into a part of her and it left unchecked, she could devour the entire world. Doubling as a means to keep her powers contained, the Inquisition uses her near-immortal body to conduct countless experiments with her. However, Takeru's recent visit stirs Kiseki's heart and she begins to awake and go out of control in her desire to see him. Kurogane is sent to deal with her but she escapes through the roof. With her body fulfilling her heart's desires, she makes her way to the city and reunites with Takeru, who is unsure of how to proceed and draws his sword against his teammates before being assured that they are not his enemy. Takeru explains his sister's circumstances, while Ikaruga tells a white lie about her true abilities in order to lessen the fears of everyone else.
The crew decide to do the long-separated siblings a favor and remotely escorts them through the city while avoiding the Inquisitors already arriving on the scene. While resting at a cafe, Kiseki asks Takeru to kill her and he outright refuses her, and pleads her to hold on for a bit longer and try her best. However, Takeru does promise to her that if the time does come where he will be forced to kill her, he will die together with her. Kiseki is utterly relieved to hear his dedication and the two happily continue their outing, only to be stopped by Kyouya. The fight comes to an end with Kurogane's arrival and Kiseki is loaded onto a truck to be taken to her new facility, where Sougetsu tells Takeru that a means to save her will be possible but he will be unable to visit her until she is fully cured. After a series of battles against Valhalla's forces, Kyouya ends up as the sole person driving her convoy vehicle and he decides to kill her, but fails to completely kill her as her powers awaken. Takeru and Ouka go alone to the center of the flesh mass to try and calm Kiseki down while the others were told to flee. Takeru's attempts to calm her down has Kiseki trying to stop her powers from fulfilling her true intentions and envelops Takeru's body and transfers a memory. Day after day of being killed over and over and Kiseki's mind eventually wished for the world that rejected her to perish. Takeru is pulled out of the vision and as he contemplates on his failure as a brother, he is assaulted by Kanaria and knocked out. Kiseki witnessed this and thought Takeru was killed and her emotions go out of control once more, causing her powers to spread further.
The 35th Platoon retreat with an unconscious Takeru while Ouka accepts Vlad's contract and covers their escape. Takeru however enters another contract with Lapis and gains God Hunter Form, and moves in to fulfill his promise with Kiseki after cutting through the rest of her flesh tendrils. The two siblings embrace and Takeru admits to his failure to protect her and readies his blade to end their lives. At the last moment, Takeru is unable to bring himself to pull through the act and the double suicide comes to a halt when Orochi temporarily annihilates Kiseki and a stand off between him and Kurogane end in a stalemate, with Takeru, Lapis, and Mari joining him while Kiseki is recovered by the Inquisition and given to the Alchemists for research.
Crimson Lotus Arc Edit
Since her fully awakened outbreak, Kiseki had, as promised, been given to the Alchemists for research by Suzaku. During the skirmish that took place in Grey City between the Inquisition troops and a contingent of Valhalla's forces, Sougetsu personally visited Suzaku to see what progress was made with finding out how her abilities worked. Suzaku had concluded that Kiseki's soul was unable to be tampered with and the only way to control her was through controlling her mentality, and Kiseki was hooked onto a machine that showed her vivid dreams to keep her pacified.
White Escape Arc Edit
It is revealed that a number of the Guillotine's users, including the vice-captain of the EXE, Scarlet Magnolia, were implanted with the cells from Kiseki's demonic flesh mass by the Alchemists. These cells granted them enhanced strength and durability but if they were stimulated too much, they would overtake their host bodies and begin to endlessly expand. Scarlet utilized her cells to discern Takeru's location and afterwards, she had her subordinates call Suzaku to strengthen Kiseki's dream-state. Scarlet activated the demonic cells again in her fight against Takeru to properly work the trajectory for her Relic Eater's bullets. However, after she is defeated, the cells begin to overtake her and Kiseki remotely senses Takeru, forcing him to enter God Hunter form to properly dispose of the expanding flesh mass.
Heretic Alliance Arc Edit
Suzaku's research had been finalized to a point where Kiseki was put into a controlled dream where she was happily content with the dream of being with Takeru. Kyouya and later, even Haunted, finds this state something to be despised and the latter decides to do something about the matter. Haunted feigns a congratulatory demeanor and gifts Suzaku with some flowers before departing and he accesses these flowers remotely to forcibly break into Kiseki's dream and reveal to her that what she's seeing are lies and demands her to awaken and fulfill what she truly wants, death and peace. Kiseki's mind finally snaps from the revelation and accepts in her heart that the happiness she was previously experiencing will be impossible and puts her mind to forcing Takeru to kill her and fully embraces the Hyakki Yakou's powers to make ensure that he will put her down and release her from life.
A short while later, the Heretic Alliance begin their raid on the First Laboratory where Takeru, Ouka, Mari, and Lapis enter the facility to find Kiseki. Kiseki's apparent awakening has however released a small amount of homoculi around the facility bearing her cells and Kyouya, who was protecting Yoshimizu's life support pod, fights back. Takeru's presence inside the facility causes the flesh mass to surge and a wall forms between the crew, seperating Takeru and Lapis from Ouka and Mari. Takeru ventures further into the facility and runs into Kyouya, where the two have their rematch over the transfer charm that could save either Kiseki or Yoshimizu, which ends with Takeru's victory. The fight is succeeded by Kiseki who finally locates Takeru and appears before him in full, bloody bloom. Takeru's attempts to convince her that her life may still be salvaged falls on deaf ears and Kiseki happily announces her intent to kill everyone he holds dear if it meant that he would come to kill her. Takeru arms himself with God Hunter form to hold her off and Ouka comes in at the right time to cancel his armor before any lasting damage occurs. Angered with seeing Ouka come to Takeru's aid, Kiseki states that she will "try her best" and escapes through the roof.
On a nearby mountain, Kiseki trudges through the forests before encountering Sougetsu, who offers her the chance to destroy the world.
Witch Hunt War Arc Edit
With Kiseki now under the "control" of the Inquisition, Sougetsu planned to use her as the fail-safe method to ensure the world's destruction. For most of the war's beginning, Kiseki remains inside the Inquisition Headquarters under Sougetsu's supervision and appeared inside his room after he ended communications from an EXE member. Sougetsu mentions that Kurogane was facing Takeru and feared that Takeru might be killed and Kiseki was insistent on leaving to save him. Sougetsu stops her and prompted her to make use of her cells embedded within a few Guillotine users near that relative area to intervene.
Later, after Takeru's duel with Orochi, Kiseki appears near him and bids him to look at the town beneath the hill and Takeru is horrified to see most of the city destroyed. Kiseki shares that she intended to make the world hers but decided that coming close to destroying it would be the last straw for Takeru and force him to kill her.
Call of Twilight ArcEdit
Kiseki is able to "consume" Ouka, Usagi, Mari, Ikaruga before she confronts and happily states to her brother at how they'll be the only ones left in the world before long. She also begins calling Takeru by name instead of usual "onii-chain". While taking certain joy from watching Takeru grimace, he is still able to say that he won't kill her and comes up with a valid response on the fact that his stubborn nature is something she wouldn't have known about him. Takeru's proposal is that they fight it out and gradually and forcibly learn each other this way. During this, Kiseki reads the memories of Usagi, Mari, and Ikaruga and attempts to "erase" their memories of him by showing them a reality where he didn't exist. However, all of them are able to break out of this dream and defy Kiseki's intentions, as well as informing that Kiseki that she wouldn't be able to break them. Kiseki's "fight" with Takeru only consisted of her commanding the mass of flesh against him, and while the latter begins to tire, Kiseki begins to get bored. Both however do not change their stance, Kiseki wishes to die together while Takeru wants her to continue living. Kiseki continues to try and force her brother's hand and prompts one of her faraway flesh masses, where both feel the earth shake and Kiseki states that around a thousand people have just from her simple command. Takeru remains adamant in not wanting to kill her and Kiseki mentions that she'll kill all of his platoon members.
Takeru's tone completely changes and Kiseki witnesses and angered Takeru for the first time. While Takeru threatens to actually kill her if he harmed his platoon members, he still declares that he won't die with if he does. Kiseki is given the choice of dying alone while being hated by Takeru or continuing to live together. Kiseki is finally broken through to and begins to consider her own actions to be the one in the wrong and as Takeru attempts to close the gap between them in this rare moment, Haunted appears to interfere. Kiseki takes this chance to escape and Takeru is forced to deal with Haunted.
Kiseki is able to make some distance between herself and Takeru and she "visits" Ouka, the latter being the one she hated the most and decided to kill first. Ouka is trapped in a dream where she is easily able to break out from the vision of apprehending Laugh Maker instead of killing her. Being the technical "closest" to Takeru, Ouka meets the brunt end of Kiseki's hate and she starts choking her. Ouka however empathizes with Kiseki's sadness and emptiness and asks her if she would spare everyone else if she were to die. The mental link shared between the two transfers Ouka's raw emotions and Kiseki is unable to properly finish Ouka off. Vlad takes this chance to get between the two and grant Ouka one last burst of magic power to help her escape. Kiseki runs off again after being unable to contain the emotions she felt and she is confronted by Ouka and rescued members of the 35th platoon. Instead of hostility, they offer their hand in friendship and they take turns in letting her know that she'd be safe among them. This hospitality further fuels Kiseki's suffering as her cleared mind fully realizes at how the damage she inflicted onto the world is unforgivable. Moments before her attempts to kill herself, Takeru arrives to comfort her. He asks if she loves him and she answers positively, saying that she loves him as "Takeru". Takeru however conveys his own feelings that he cannot reciprocate that sort of love back to her but cannot deny the "love" he feels for her is still real. Takeru confesses his own feelings but expresses the love between siblings and Kiseki begins to cry and as she forms the words to finally mend their relationship, she is shot by Innocentius. As Sougetsu arrives and afflicts Mari to fight Ouka, he orders for Kiseki to continue devouring the world.
Promise of Dawn Arc Edit
While the 35th Platoon regroup, Kiseki is commanded by Sougetsu to continue her previous intent to consume the world and flesh-like trees begin to sprout more demonic spawns as well as constant flesh protrusions that continue to consume everything in sight. The 35th Platoon are confronted by a fully concentrated "demon" variant capable of utilizing magic. With Kiseki's very soul under Sougetsu's influence, her "body" took shape of a soulless demon that was the amalgamation of the Kusanagi family's curse over the centuries .It's appearance mimics a traditional woman of the Kusanagi Clan and it appeared to be the accumulated incarnation of the family's curse. Ouka's inability to comprehend its workings leaves its spells unable to be dispelled while Lapis' attempts to absorb its magic ends up harming her. Forced to fight her without the aid of magic, the platoon work in tandem to break its barrier. They succeed in weakening it and Kanaria arrives to finish it off and the team is joined by the united remnants of the Inquisition, Valhalla, and the Heretic Alliance. Once Sougetsu and Takeru are transported to the mythological world, Kiseki's soul is freed and is left unconscious.
As the Inquisition was reconstructed after the calamitous war, Kiseki was officially recognized by the outside world but information of her real nature was suppressed by the remaining Inquisition officials. Nagaru, Ikaruga, and Kurogane vouched that Kiseki was to be handled by the Inquisition again, only this time with more care and less inhumane experimentation. Ikaruga is given charge of Kiseki's treatment and the Inquisition's underground holding facilities are converted to Kiseki's personalized lab and home. Ikaruga took over as Kiseki's primary "caretaker" and spent most of her work conducting experiments in finding a way to cure her. Her continued experimentation was something that Kiseki herself stressed and her shift in attitude was apparent when she began to trust others. In particular, she began trusting Ikaruga immensely and viewed her as an older-sister figure while Usagi became a close friend who taught her how to cook and sew. Kiseki was however very obstinate in allowing her brother to enter a relationship with the others as she still pursued him as a romantic partner. She used her own affection, however, to keep a constant insurance on her abilities and had both herself and Takeru collared with a Gleipnir, keeping her own mentality in check as the fear of killing her brother was always there. Kiseki had become accustomed to her new lifestyle and was soon enrolled into the renovated academy.
Hyakki Yakou: Classified as the ancient Demon attribute, the Hyakki Yakou is the amalgamation of countless demons sealed within Kiseki that are outwardly manifested as a mass of flesh that are decorated with countless mouths and eyes. This curse originated with the pact between the ancient onmyouji and the ancestors of the Kusanagi Clan that carried the burden of containing the demon threat within their family. This flesh mass has a will of its own that is separate from Kiseki but it holds to an absolute will that it "grants Kiseki's wishes" which protects her from outside harm and moving in accordance to her desire. While Kiseki had rejected her body, when fully united, she can fully utilize it to fit her needs.
- Immortality: The Hyakki Yakou's body can infinitely regenerate, giving Kiseki near immortality whether she wanted it or not. This fact was mostly exploited by the Inquisition's researchers where she was the primary test subject in their experiments that both tried to ascertain what she was and also test weapon capabilities.
- Assimilation: Whatever the Hyakki Yakou "consumes" adds to the ever-growing flesh mass that it is composed of. Anything can be assimilated into the variant but with further control, Kiseki can discern what she consumes and doesn't want to. This power extended to "corrode" even materials of magical origin.
- Flesh Manipulation: The flesh mass can bend and rearrange its form to suit Kiseki's needs. Cases of this are primarily Kiseki's "wings" that the flesh can transform into to grant her flight. The flesh can also harden themselves to create weapons.
- Brain Contact: Kiseki can apparently contact with the dreams and memories of the targets that are held within the flesh mass. She can read their memories, induce dreams for them to see, and even feel the emotions of those she is "connected" with.
- Spawns: Kiseki can "separate" her flesh mass and have them grow independently of her while still remaining connected to her consciousness. The Inquisition were able to harvest small samples of her "demonic" cells and implant them to a number of their Dullahans that granted them temporarily increased strength but at an enormous risk of overstimulating these cells that more often than not, overtook their host bodies.
- Remote Spawns: When enough mass is consumed, Kiseki's pillars of flesh can sprout tree-like constructs that can continously spawn mindless creatures that attack anything in sight.
- Her name ironically translates to "miracle".