History Fanfic / BladeOfDemonSalvation

** 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 [[NoGoodDeedGoesUnpunished 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 MercyKill him. Before [[DyingAsYourself 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.

* SmallRoleBigImpact: The {{Original Character}}s 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 [[TookALevelInKindness 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 MercyKill 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.

* ForWantOfANail: 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 MercyKill 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.

* MindControl: 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.

''Blade of Demon Salvation'' is a ''Manga/DemonSlayerKimetsuNoYaiba'' AlternateUniverseFic written by [=Manu259=] that mostly follows the plot of the original story, but also [[ForWantOfANail adds some changes to the plot]] ([[AscendedExtra such as making minor characters in the source material more important]] and [[SparedByTheAdaptation or allowing characters that died early to live here]]) that still allows it to provide a more unique take on the story.

* ReasonableAuthorityFigure: 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) 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.

** Subverted with 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.

** Averted 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.

* AdaptationalJerkass: Zig-Zagged with Muzan's characterization. At no point in canon is Muzan ever presented as a good person, at best only having small PetTheDog moments with Kyogai and Rui[[note]]Sparing Kyogai and dismissing him from the Twelve Demon Moons instead of killing him and giving Rui a certain amount of freedom[[/note]]. Here, Muzan is actually shown pulling a YouHaveOutlivedYourUsefulness 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 [[YouHaveFailedMe 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 [[spoiler:if one takes the latter's canon backstory into account and learns that she was made to be loyal to Muzan]].

* GravityMaster: 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 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.

* PeoplePuppets: Lower Moon 4 Mukago's Blood Demon Art allows her to take control of people as puppets to fight for her.

* AdaptationExpansion: Some scenes or character's backstories are expanded on, some of which were never shown in the manga, or through the use of flashbacks:

* AgreeToDisagree: In contrast to canon when Giyu tells Tanjiro that he shouldn’t feel sympathy for demons after the former kills Rui, 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.

* BigDamnHeroes: Instead of Giyu, Makomo and Sabito are the ones who come to the rescue of Inosuke and Tanjiro when they're about to be killed by the "Father" Spider Demon and Rui.

* DeathByAdaptation: [[spoiler:In canon, Rei and her daughter are never seen again after Muzan sends them back home, [[WhatHappenedToTheMouse leaving their fate unknown]]. Here, he actually has them killed by one of his demons after deciding they've become loose ends, though the deaths are mercifully not shown.]]

* FirstEpisodeTwist: 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, 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. [[EstablishingSeriesMoment 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.]]

* YouHaveOutlivedYourUsefulness: 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 has them killed by one of his minions.

** Kaigaku [[AdaptationalEarlyAppearance 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.

* FaceMonsterTurn: 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 eaten several humans. Tamayo's spell allows Shohei to reawaken his human mind long enough to beg Tanjiro to MercyKill him as he doesn't want to live on as a demon, with Tanjiro reluctantly obliging.

* GodzillaThreshold: 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 giving some of her blood to Genya to activate his ability[[/note]] in order to turn the tides against the enemy and save their fellow Demon Slayers.

* HisNameIs: After Tanjiro is forced to MercyKill 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 with Shohei's headless body ends up destroying what's left of it, preventing Shohei from telling Tanjiro anything important.

* YouHaveFailedMe: Subverted. When Susamaro is forced to retreat from her mission to hide from the sun, Muzan says this 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.
* YouHaveOutlivedYourUsefulness: Muzan, deciding his "family" are now loose ends after he's discovered in Asukasa by two Demon Slayers, takes them to the Infinity Castle and has them killed by one of his minions. Averted with the Lower Moons unlike in canon though, since while Muzan still decides to disband the Lower Moons, 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.

** Because Rokuro, Mukago, and Susamaru get original {{Story Arc}}s to themselves, Tanjiro and his friends will inevitably get to spend more time with Kyojuro Rengoku before they confront Enmu in the Mugen Train mission.

* AllLovingHero: Tanjiro is this, even more so than in canon. While Canon!Tanjiro would still kill demons if they're hostile and will MercyKill 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 MercyKill 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.

* FriendToAllChildren: Makomo enjoys 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.

* AdaptationalHeroism: 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.
* AdaptationalJerkass: Zig-Zagged with Muzan's characterization. At no point in canon is Muzan ever presented as a good person, at best only having small PetTheDog moments with Kyogai and Rui[[note]]Sparing Kyogai and dismissing him from the Twelve Demon Moons instead of killing him and giving Rui a certain amount of freedom[[/note]]. Here, Muzan is actually shown pulling a YouHaveOutlivedYourUsefulness 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 [[YouHaveFailedMe 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 [[spoiler:if one takes the latter's canon backstory into account and learns that she was made to be loyal to Muzan]].

** Lower Rank 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.

* GravityMaster: Lower Rank 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 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.

* PeoplePuppets: Lower Rank 4 Mukago's Blood Demon Art allows her to take control of people as puppets to fight for her.

* AdaptationalExpansion: Some scenes or character's backstories are expanded on, some of which were never shown in the manga, or through the use of flashbacks:

* AdaptationalJerkass: Zig-Zagged with Muzan's characterization. At no point in canon is Muzan ever presented as a good person, at best only having small PetTheDog moments with Kyogai and Rui[[note]]Sparing Kyogai and dismissing him from the Twelve Kizuki instead of killing him, and giving Rui a certain amount of freedom[[/note]]. Here, Muzan is actually shown pulling a YouHaveOutlivedYourUsefulness 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 Ranks 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 [[YouHaveFailedMe 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 [[spoiler:if one takes the latter's canon backstory into account and learns that she was made to be loyal to Muzan]].

** When Kyogai explains to Tanjiro that he was trying to eat Kiyoshi so he can get back his rank among the Twelve Kizuki, 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.

** Susamaro, after avoiding her canon fate, gets to become one of the Twelve Kizuki just as she wanted, taking Rui's place as Lower Rank 5 following his death.
** Rokuro and Mukago of the Lower Ranks, after adapting to Muzan's blood being injected into them, are given one last chance by Muzan to prove their worth, becoming {{Arc Villain}}s in an original StoryArc.

* FirstEpisodeTwist: 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, 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 Hashira while Giyu is his Tsuguko. [[EstablishingSeriesMoment 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.]]

** Both Sabito and Makomo survive the Final Selection, which allows the former to become the Water Hashira and the latter to be just as strong as a Hashira. Giyu becomes the Tsuguko of Sabito, and the pair serve as Tanjiro's primary mentors and supporting figures throughout the story.

* PragmaticVillainy: Downplayed, but still noticeable in Muzan's case when compared to canon. Rather than kill all of the remaining Lower Ranks 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 Hashira or Tanjiro. He justifies this by saying that since he had just inducted Susamaro into the Lower Ranks, 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.

* VillainTeamUp: Rokuro and Mukago of the Lower Ranks forge an alliance so that each of them will be able to kill one of Muzan's targets.

* YouHaveOutlivedYourUsefulness: Muzan, deciding his "family" are now loose ends after he's discovered in Asukasa by two Demon Slayers, takes them to the Infinity Castle and has them killed by one of his minions. Averted with the Lower Ranks unlike in canon though, since while Muzan still decides to disband the Lower Ranks, 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 Hashira or Tanjiro.

* FirstEpisodeTwist: 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, 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 Hashira 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 plots and character roles.

* PragmaticVillainy: 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 Hashira 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.

* SafetyFreak: 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 seems small and not life-threatening, and wouldn't take no for an answer from either Makomo or Giyu.

* AdaptationalJerkass: Zig-Zagged with Muzan's characterization. At no point in canon is Muzan ever presented as a good person, but it is hinted [[spoiler:that he at least spared the lives of Rei and her daughter and simply left them when they were no longer needed]]. Here, Muzan is actually shown pulling a YouHaveOutlivedYourUsefulness on them, letting one of his demons kill them while openly declaring they're useless to him. His treatment of the Lower Ranks 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. 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 [[YouHaveFailedMe 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.

** 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 Hashira. Giyu becomes the Tsuguko of Sabito, and the pair serve as Tanjiro's primary mentors and supporting figures throughout the story.

* AdaptationalJerkass: Zig-Zagged with Muzan's characterization. At no point in canon is Muzan ever presented as a good person, but it is hinted [[spoiler:that he at least spared the lives of Rei and her daughter and simply left them when they were no longer needed]]. Here, Muzan is actually shown pulling a YouHaveOutlivedYourUsefulness on them, letting one of his demons kill them while openly declaring they're useless to him. His treatment of the Lower Ranks 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. 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 [[YouHaveFailedMe 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 remember she was made to be loyal to Muzan.

** Rokuro and Mukago of the Lower Ranks, after adapting to Muzan's blood being forcefully injected into them, are given one last chance by Muzan to prove their worth, becoming {{Arc Villain}}s in an original StoryArc.

* DeathByAdaptation: [[spoiler:In canon, Rei and her daughter are never seen again after Muzan sends them back home, though it is hinted that he spared their lives and left them when they were no longer needed. Here, he actually has them killed by one of his demons after deciding they've become loose ends, though the deaths are mercifully not shown.]]

** Lower Rank 3 Wakaruba, rather than get 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.

* AdaptationalJerkass: Zig-Zagged with Muzan's characterization. At no point in canon is Muzan ever presented as a good person, but it is hinted [[spoiler:that he at least spared the lives of Rei and her daughter and simply left them when they were no longer needed]]. Here, Muzan is actually shown pulling a YouHaveOutlivedYourUsefulness on them, letting one of his demons kill them while openly declaring they're useless to him. His treatment of the Lower Ranks 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. 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 [[YouHaveFailedMe killing her for failing her mission]], though he does warn her that he won't show her any mercy again.