Fanfic / Blade of Demon Salvation

Blade of Demon Salvation is a Demon Slayer: Kimetsu no Yaiba Alternate Universe Fic written by Manu259 that mostly follows the plot of the original story, but also adds some changes to the plot (such as making minor characters in the source material more important and or allowing characters that died early to live here) that still allows it to provide a more unique take on the story.

The fanfiction can be found on here and here.

This story assumes you have read the original manga, so beware of spoilers.

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This fanfiction contains examples of:

• Adaptational Heroism: Because Tanjiro spares her life and offers her a chance to live without having to eat humans, the Spider Demon Mother becomes an ally to Tanjiro and his friends, promising never again to eat humans as she becomes an assistant to Tamayo.
• Adaptational Jerkass: Zig-Zagged with Muzan's characterization. At no point in canon is Muzan ever presented as a good person, at best only having small Pet the Dog moments with Kyogai, Rui, and Akaza^note He spares Kyogai and dismisses him from the Twelve Demon Moons instead of killing him, gives Rui the freedom to enact his family fantasy, and respects Akaza’s decision to not eat women.. Here, Muzan is actually shown pulling a You Have Outlived Your Usefulness on his first shown human family, letting one of his demons kill them while openly declaring they're useless to him, whereas the family is never seen again in the manga after Muzan sends them home, leaving their fates unclear. His treatment of the Lower Moons is less callous than in canon, simply giving them four months to prove their worth to him, but it's clear this is only done out of pragmatism rather than kindness. He still kills Kanamue when he scoffs at Muzan's criticism in his mind, and when Wakuraba dies as a result of being unable to adapt to Muzan's blood, the latter shows nothing but complete apathy. When Susamaru flees from her mission, her utter devotion to Muzan and willingness to accept her punishment is what convinces him to spare her life instead of killing her for failing her mission, though he does warn her that he won't show her any mercy again. This actually makes his relationship with Susamaru more disturbing if one takes the latter's canon backstory into account and learns that she was made to be loyal to Muzan.
• Adaptation Expansion: Some scenes or character's backstories are expanded on, some of which were never shown in the manga, or shown through the use of flashbacks:
  • Muzan Kibutsuji is shown with Rei and her daughter in a flashback encountering a Demon Slayer after he had escorted Haruka to the Police Station. This incident, as well as Tanjiro's arrival, leads Muzan to decide the family are now a liability and has them killed by a demon.
  • A flashback reveals how Kanao went to the Final Selection without consulting with Shinobu, a decision that scared Shinobu out of her wits and leads her to scold her sister after she returns, before accepting her decision to become a Demon Slayer after learning she made those decisions without relying on her coin.
  • Because Rokuro, Mukago, and Susamaru get original Story Arcs to themselves, Tanjiro and his friends will get to spend more time with Kyojuro Rengoku before they inevitably confront Enmu in the Mugen Train mission.
• Agree to Disagree: In contrast to canon when Giyu tells Tanjiro that he shouldn’t feel sympathy for demons after the former kills Rui (at least before he recognized Tanjiro), Sabito admits to Tanjiro that he can’t really share his feelings towards demons after he kills Rui and sees Tanjiro comfort him, but he’ll still respect them.
• All-Loving Hero: Tanjiro is this, possibly even more so than in canon. While in canon, Tanjiro would still kill demons if they're hostile and will Mercy Kill demons that surrender, he is willing to show compassion for them and pray for their souls. Here, due to seeing Muzan turn a random civilian into a demon and being forced to Mercy Kill a recently turned Soda Shohei, Tanjiro is actually willing to spare demons that surrender and offer them a chance to live if they stop eating humans, sending them over to Tamayo so she'll help them get a second chance.
• And I Must Scream: Those controlled by Miko's parasites are shown to be in great pain and implied to be conscious of what's going on. The demon priest in particular is shown to be in great agony when Miko forces him to follow orders, to the point when he's finally decapitated by Tanjiro, he actually thanks the boy for ending his suffering.
• Armor-Piercing Question:
  • When Kyogai explains to Tanjiro that he was trying to eat Kiyoshi so he can get back his rank among the Twelve Demon Moons, Tanjiro asks him why he even wants it back. Kyogai reacts angrily to the question, only to realize that he honestly doesn’t know the answer.
  • When Kaigaku calls Zenitsu trash, a furious Shoichi rightfully calls him out on it by pointing out that Zenitsu slayed the demon that Kaigaku was having trouble against, then asks if Zenitsu is trash, what does that make Kaigaku. Despite giving the boy a Death Glare, Kaigaku just walks away, apparently affected by those words.
  • When Sanemi finds out about Genya's ability, he tries to take his eyes to force him to quit, justifying it by saying that makes him a demon as well. Giyu proceeds to anger Sanemi when he asks him why he doesn't just cut his head off then.
• Ascended Extra: Minor characters in the original manga become more important in this story. Several examples include:
  • Sabito and Makomo, who were Dead All Along and served as Tanjiro's Spirit Advisors, survived their canon fate and serve as Tanjiro's primary mentors in the Water Breathing style and as Parental Substitutes.
  • Ozaki acts as a supervisor for Tanjiro in his first mission, witnesses both Nezuko emerging from Tanjiro's box as well as Genya's power, and also provides her testimony and support during Tanjiro's trial.
  • Genya Shinazugawa becomes a major character earlier in the story after his Fire-Forged Friendship with Tanjiro, to the point of becoming one of the main characters.
  • Kanao, after getting a chance to bond with Tanjiro, joins his circle of friends and becomes a main character.
  • Susamaro, after avoiding her canon fate, gets to become one of the Twelve Demon Moons just as she wanted, taking Rui's place as Lower Moon Five following his death.
  • Rokuro and Mukago of the Lower Moons, after adapting to Muzan's blood being injected into them, are given one last chance by Muzan to prove their worth, becoming Arc Villains in an original Story Arc.
  • The Spider Demon Mother (who is given the name Ito by Genya), as a result of Tanjiro sparing her life, becomes an important ally after being escorted to Tamayo's clinic and becoming an assistant to the latter.
  • Kaigaku appears earlier in the story as a Demon Slayer and a reluctant supervisor to Tanjiro and Zenitsu during the mission to investigate the Tsuzumi Mansion. He also takes part in the mission to eliminate the Spider family in Natagumo mountain, fights with Tanjiro when it's discovered the latter is traveling with a demon and provides his testimony during Tanjiro's trial.
  • Downplayed with Tamayo and Yushiro. They were always important characters in canon, but they only had major roles in the Asakusa Arc and didn't appear again until the final battle of the manga, being mostly left in the background working on creating the cure for demonization. Here, they get more scenes and focus, with Tanjiro even paying them a visit when Genya and Ito take him to Tamayo's clinic. They also end up taking in any demon Tanjiro sends their way.
• Bait-and-Switch Boss: The Arc Villain of Chapters 7-10 is built up to be a demon priest who can create psychic hands to push away enemies. However, it turns out he was actually being controlled by Miko with a demonic parasite, and he actually thanks Tanjiro for freeing him through a Mercy Kill.
• Because You Were Nice to Me: Tanjiro sparing the Spider Demon Mother and offering her a chance to live without having to eat humans lead the latter to accept his offer and help Genya escort him to Tamayo's clinic. This also makes Tanjiro a Morality Pet to her, as she also goes out of her way to avoid killing the other Demon Slayers standing in her way because it would mean betraying his trust.
• Big Damn Heroes: Instead of Giyu, Makomo and Sabito are the ones who come to the rescue of Inosuke and Tanjiro respectively when they're about to be killed by the "Father" Spider Demon and Rui.
• Breather Episode: Chapters 17 and 31, two of the Interlude chapters, serve as this. The former has Tanjiro, Nezuko, Zenitsu, and Inosuke recovering at a Wisteria House following the fight at Tsuzumi Mansion as in canon. The latter has Tanjiro visit the Butterfly Mansion to recover from his wounds following the first battle against Rokuro, where he gets the chance to bond with Kanao, leading the latter to join his squad.
• Death by Adaptation: In canon, Rei and her daughter are never seen again after Muzan sends them back home, leaving their fate unknown. Here, he actually has them killed by a demon after deciding they've become loose ends, though the deaths are mercifully not shown.
• Dies Differently in Adaptation:
  • Lower Moon 3 Wakaruba, rather than getting decapitated by Muzan and unable to regenerate like in canon, instead dies when he is unable to adapt to Muzan's blood being injected into him and gets reduced to a puddle of blood.
  • Instead of both of them being killed by Giyu, the Father Spider Demon and Rui are killed by Makomo and Sabito respectively.
• Even Evil Has Standards: Rokuro and Mukago both find Enmu creepy, with Mukago even admitting she would never consider forming an alliance with him.
• Everyone Has Standards: While Tanjiro, Ukogi, and Shoichi are understandably not fond of Zenitsu's cowardly and overdramatic antics, they don't approve of the way Kaigaku treats him, showing disgust with his callous bullying and disregard of Zenitsu's well-being to the point they're not afraid to call him out on it and speak in Zenitsu's defense.
• Face–Monster Turn: Soda Shohei, the Demon Slayer who was meant supervise Tanjiro in the Akakusa mission, ends up suffering the misfortune of encountering Muzan when he escorts Haruka to the police station. Soda gets captured by Muzan and injected with his blood, turning him into a feral demon. By the time Tanjiro meets him personally, Shohei had already killed and ate humans. Tamayo's spell allows Shohei to reawaken his human mind long enough to beg Tanjiro to Mercy Kill him as he doesn't want to live on as a demon, with Tanjiro reluctantly obliging.
• Fire-Forged Friends: Tanjiro and Genya originally had a hostile relationship, mainly because Tanjiro snapped Genya's wrist when the latter assaulted Kanata Ubayashiki. After being forced to work together against Miko and learning the other's secret, the two start to become close friends, allowing Genya to become more of a team player.
• First-Episode Twist: The first chapter plays out like it does in canon, with Giyu sparing the demonized Nezuko when she goes out of her way to protect Tanjiro instead of eating him, while instructing the latter to go to Urokadaki. Then the end of the chapter cuts to Giyu reporting what happened to Sabito, who is not only still alive in this story, but is also the Water Pillar while Giyu is his Tsuguko. This immediately lets us know that while the story might go on a similar path to canon, there will definitely be some noticeable changes in the plot and character roles.
• Friend to All Children: Makomo likes visiting the Butterfly Mansion partially because she enjoys hanging out with Sumi, Kiyo, and Naho, even going so far as to teach them how to make flower crowns.
• Godzilla Threshold: When Tanjiro and Genya are forced to fight the Demon Slayers being controlled by the Spider Demon Mother's strings, the two are forced to reveal to their respective secrets^note Tanjiro having his sister come out of the box and give some of her blood to Genya to activate his ability in order to turn the tides against the enemy and save their fellow Demon Slayers.
• Gravity Master: Lower Moon 2 Rokuro's Blood Demon Art allows him to alter the flow of gravity to either send his enemies flying in a different direction or launch the walls or objects at them at high speeds. He can also increase the gravitational force in the area, though doing so also affects him to the point that the higher gravity can hurt him.
• Heel–Face Turn: The Spider Demon Mother goes through this once Tanjiro spares her life and gives her a chance to live without having to eat humans.
• Heroic Willpower: Yoriichi Tsugikuni, despite being turned into a demon by Muzan, still retains enough strength of will to defy him and continue dueling Kokushibo for centuries, with Muzan barely able to make him bow to him.
• His Name Is...: After Tanjiro is forced to Mercy Kill the demonized Soda Shohei, Soda's mouth ends up turning to ash before he can speak to Tanjiro, but he still wills his disappearing body into attempting to carve a message about Muzan so Tanjiro can take the information to the Pillars. Unfortunately, this triggers Muzan's curse as the latter's cells within Shohei's headless body ends up destroying what's left of it, preventing Shohei from telling Tanjiro anything important.
• Horror Hunger: This is one of the reasons Tanjiro sympathizes with demons. Demons cannot eat anything but human flesh and blood, with Nezuko being the only exception. Many demons that started out tragic had likely consumed people they care about against their will, and if they don't eat any humans, they'll lose control of themselves and attack humans to eat them. This ends up being part of the reason Tanjiro tries to redeem some demons and sends them over to Tamayo so she can eliminate the craving for human flesh.
• I Cannot Self-Terminate: Soda Shohei is turned into a feral demon by Muzan, but his human mind temporarily reawakens as a result of Tamayo's spell. He begs Tanjiro to Mercy Kill him before he causes anymore harm and genuinely doesn't want to live on as a demon. Tanjiro reluctantly obliges with his request.
• Meaningful Name: Ito is the Japanese word for "string", which fits the name Genya gives to the Spider Demon Mother due to her mastery over strings.
• Mercy Rewarded: A non-video game example. Tanjiro spares the Spider Demon Mother when she surrenders and offers her a chance to live without having to eat humans. She would later help Genya escort Tanjiro to Tamayo's clinic after he gets injured trying to protect Nezuko from the other Demon Slayers, with Genya trying to escort him to safety, becoming an ally to the two in the process.
• My Fist Forgives You: After Sabito performs his Secret Test of Character on Nezuko, he apologizes to Tanjiro despite explaining why it was necessary. Tanjiro agrees to forgive him on the condition that he allows him to headbutt him, which Sabito accepts and gets knocked out as a result.
• Named by the Adaptation:
  • Muzan's "daughter" is given the name Haruka, whereas her name in canon is never revealed.
  • The Spider Demon Mother is given the name Ito by Genya following her defection from Rui's "family".
• O.O.C. Is Serious Business: Everybody at the Butterfly Mansion is stunned by Kanao's change in behavior after Tanjiro and his friends leave to go to the Flame Estate, namely when Kanao helps with the chores and actually buys sweets for Kiyo, Sumi, and Naho. Aoi is notably the most shocked by the fact that Kanao actually bought sweets for the girls without them asking or prompting her to do so, as well as the fact that she actually bought the sweets with her own money.
• Original Character:
  • Miko, the Arc Villain of chapters 7-10, is a demon with the power to turn both demons and humans into her puppets by planting parasitic insect-like creatures into their bodies. She takes over a town in order to discretely feed on humans and their fear without having to alert the Demon Slayer Corps to her operations. She also serves as a Decomposite Character to the Swamp Demon, where instead of the latter, Tanjiro attempts to interrogate her about Muzan, leading her to show her fear of the Progenitor of Demons to the point of refusing to tell him.
  • Soda Shohei is a Demon Slayer who was ordered to supervise Tanjiro in Asakusa on a mission, only to end up crossing paths with Muzan when he escorts his "daughter", Haruka, to the police station. This leads Muzan to turn him into a demon against his will, which ends up indirectly saving Susamaro's life when the recently demonized Shohei ends up interfering with Tamayo's attempt to invoke Muzan's curse on his subordinate, forcing Tanjiro to fight and Mercy Kill him. Before dying as himself, he attempts to tell Tanjiro Muzan's location only for Muzan's curse to destroy his body, though Tanjiro still promises that he will find out what Shohei was trying to tell him, and this encounter also gives Tanjiro the motivation to give repentant demons a chance to live.
• People Puppets: Lower Moon 4 Mukago's Blood Demon Art allows her to take control of people as puppets to fight for her. They don't seem to be conscious at all while being controlled.
• Point of Divergence: While this fanfiction mostly follows the canon plot, there are noticeable differences:
  • Both Sabito and Makomo survive the Final Selection, which allows the former to become the Water Pillar and the latter to be just as strong as a Pillar. Giyu becomes the Tsuguko of Sabito, and the pair serve as Tanjiro's primary mentors and supporting figures throughout the story.
  • When Tanjiro suggests that multiple Demon Slayers can work together, Sabito brings up the idea to pair Demon Slayers together in groups, having the newly inducted be supervised by a more experienced Demon Slayer. This helps to reduce casualties by 10% and allows the Demon Slayers to start working more efficiently as a group. This also allows Tanjiro to befriend Genya and have him become a part of his group.
    • This in turn also leads Tanjiro to see a Demon Slayer meant to be his overseer in Asakusa Town having already been turned into a demon by Muzan, forcing him to Mercy Kill him. This becomes part of Tanjiro's motivation give repentant demons a chance to live and atone, leading him to spare the Spider Demon Mother and allowing her to become Tamayo's assistant.
• Pragmatic Villainy: Downplayed, but still noticeable in Muzan's case when compared to canon. Rather than kill all of the remaining Lower Moons for being too weak, Muzan decides to give them a portion of his blood and as well as one last chance to prove their worth by giving them four months to either kill one of the Pillars or Tanjiro. He justifies this by saying that since he had just inducted Susamaro into the Lower Moons, it would be too wasteful to just kill them now and he instead came up with a method to dispose of them that would prove more beneficial to him.
• Pummeling the Corpse: After Kaigaku decapitates Kyogai with the help of Tanjiro, he starts kicking the body just to rub in his victory. A disgusted Tanjiro immediately puts a stop to it, telling him that whether their enemy is a demon or not, they shouldn't be kicking corpses.
• Reasonable Authority Figure: Kagaya Ubuyashiki hears out Sabito's suggestion in pairing Demon Slayers together in squads and his suggestion to pair new members with middle-ranked members to assess their skills, and after hearing the Pillar's thoughts on it and their approval, agrees to test it out. When he hears from Sabito about how he, Makomo, Giyu, and Urokadaki have spared a non-hostile demon and have been keeping her existence a secret, he comes to the former three's house personally to talk about the demon and puts a stop to the fighting. After hearing the whole story about Nezuko from the three and seeing her character for himself, he immediately stops the hunt for Nezuko and has Tanjiro come peacefully to the trial once he makes it back. He allows every question relevant to the trial to be asked and answered, has witnesses testify to prove that no one was brainwashed, and after hearing of how Genya can temporarily take on a demon's traits, still allows him to be a part of the Corps, albeit after a check-up from Shinobu to make sure nothing is wrong with him. After hearing of the Pillar's opinion about Nezuko, he makes a compromise about the differing opinions about Nezuko by having her, Tanjiro, and Genya supervised by a Pillar. After Amane reads Tamayo's letter to him, Kagaya notes the complications behind it (namely how some Demon Slayers might oppose it and most demons don't even want to be human again) and decides to wait until the time is right to bring it up to the Corps, only discussing it with the Pillars one-by-one.
• Safety Freak: Shinobu lampshades that Sabito tends to be a real worrywart when it comes to Makomo's wellbeing. He actually insists to Makomo to go get her left arm treated by Shinobu even though the wound doesn't seem to be life-threatening and wouldn't take no for an answer from either Makomo or Giyu.
• Secret Test of Character: After Nezuko wakes up from her 2-year sleep, both Sabito and Makomo place her through one to see if she truly won't kill humans. While Makomo holds Tanjiro down to keep him from interfering, Sabito attacks Nezuko, who avoids all of his sword swings without fighting back. When she sees her brother in trouble, Nezuko immediately tries to go to his rescue, avoiding Sabito's attacks, and stands down willingly and presents her neck when Sabito offers to let her brother go if she surrenders. This is what convinces the two Demon Slayers that Nezuko can be trusted.
• Ship Tease:
  • There are several moments between Sabito and Makomo to the point they are a couple in all but name.
  • Tanjiro and Kanao go through some of these after they start to bond and share their pasts.
• Small Role, Big Impact: The Original Characters mentioned above, despite lasting for only a short amount of time before being killed by Tanjiro, each have a major impact on Tanjiro's story. For Miko, Tanjiro and Genya's fight against her leads the two of them to discover the other's secret and become friends, allowing Genya to become a nicer person earlier than in canon and also sets up the circumstances where the two would eventually become part of the same squad. In Soda Shohei's case, being turned into a demon and begging Tanjiro to Mercy Kill him becomes part of the reason Tanjiro seeks to give repentant demons a chance to live and atone for their sins, leading him to ask Tamayo to take in repentant demons he sends over to her clinic. The demonized Soda's interference with Tamayo's attempt to make Susamaro invoke Muzan's curse allows her to escape and genuinely become one of the Twelve Demon Moons by replacing Rui as Lower Moon 5 after the latter is killed by Sabito.
• Spared by the Adaptation: Several characters that died in canon are shown to be alive in this fanfiction.
  • Sabito and Makomo, who were revealed to have been killed in the Final Selection, are actually still alive in this story and become supporting figures in Tanjiro's journey.
  • The Spider Demon Mother is spared by Tanjiro rather than Mercy Killed after seeing her surrender, leading her to become an ally.
  • Ozaki is saved from her canon fate by the combined efforts of Tanjiro, Nezuko, and Genya, leading her to become a witness giving her testimony in Tanjiro's trial.
  • Yoriichi Tsugikuni is revealed to not only still be alive but has been forcefully turned into a demon by Muzan as the latter tries to force him to submit to his will, all the while he continues to fight off his influence for hundreds of years and continue dueling his brother.
• Spared, but Not Forgiven: Downplayed with Tanjiro and Genya's relationship with Ito, the Spider Demon Mother.
  • When Tanjiro offers her a chance to live if she stops eating humans, the confused demon asks why he would offer her this and if he's just going to forgive her for her sins. Tanjiro immediately tells her that it's not his place to forgive demons, and it's possible she may never be forgiven, but he'll still show mercy to repentant demons because being a demon doesn't make one evil. Because of this, Tanjiro treats her with kindness after she accepts his offer.
  • When Genya learns that Ito was the demon who forced his fellow Demon Slayers to fight and kill each other, he has conflicted feelings. He admits he still can't forgive demons for the murders they caused, but Tanjiro's reason for sparing Ito's life causes him to decide to at least give Ito a chance to prove herself.
• Speaking Up for Another: Although Tanjiro, Ukogi, and Shoichi aren't fond of Zenitsu's cowardly and over-dramatic antics, they don't approve of the way Kaigaku treats him and aren't afraid to call him out on it and speak in Zenitsu's defense. When Kaigaku dismisses the unconscious and bleeding Zenitsu as trash, a furious Shoichi rightfully calls him out on it.
  Shoichi: Tra-?! Zenitsu-san was the one that defeated that demon that was giving you trouble, if he is trash then what does that make you?!
• Team Member in the Adaptation: In canon, Tanjiro's team consisted of himself, Nezuko, Zenitsu, and Inosuke. Here, Genya and Kanao get to become teammates with the quartet.
• Trauma Button: Ito, despite leaving the Spider Family, still retains traumatic memories of Rui's abuse, which leads her to have a panic attack after realizing she had unwittingly turned into her original child form. It takes a Cooldown Hug from Tamayo and reassurance from her for Ito to calm down.
• Villain Team-Up: Rokuro and Mukago of the Lower Moons forge an alliance so that each of them will be able to kill one of Muzan's targets.
• You Are Better Than You Think You Are:
  • After Kanao tells Tanjiro of how she was abused and sold into slavery before being adopted as Kanae and Shinobu's sister, she tells him of how it's because there was always something wrong with her, only for Tanjiro to immediately tell her that if anyone can go through that experience and still be alright, then he can't help but think there was something wrong with them to begin with. Tanjiro clarifies that there is nothing wrong with Kanao, reassuring her that what is wrong is what her parents did to her and how that affected her.
  • The above conversation leads Kanao to recall how Kanae treated a wound on her leg, and when Kanae hears that Kanao didn't say anything about the wound because she'll get hurt more if she says it hurts, a saddened Kanae reassures her nobody at the Butterfly Mansion will hurt her for saying something hurts and she can always talk to them if she has problems. When Kanao asks if she was abused because there's something wrong with her, Kanae firmly but gently tells her no, reassuring her that there is nothing wrong with her and promises that one day she'll be able to open her heart and make a decision for herself once more.
• You Have Failed Me:
  • Subverted when Susamaro is forced to retreat from her mission to hide from the sun. Muzan says this trope near-verbatim to her, but Susamaro being willing to accept her punishment is what convinces him to spare her life, though he warns her that he will not tolerate any failure from her again.
  • Subverted with the Lower Moons unlike in canon, since while Muzan still decides to disband the Lower Moons after Rui's death, he is willing to give them one last chance to prove their worth to him by giving them four months to either kill one of the Pillars or Tanjiro.
• You Have Outlived Your Usefulness: Muzan, deciding his "family" in Asakusa are now loose ends after he's discovered by two Demon Slayers, takes them to the Infinity Castle and leaves them to be killed by a demon.