History NightmareFuel / DemonSlayerKimetsuNoYaiba

* Chapter 96: Ume/Daki and Gyutaro's past turns out to be even worse than Rui's, with NightmareFuel and TearJerker in equal parts. Their mother was a prostitute in the poorest area of the Entertainment District (by the way, such environment is HarmfulToMinors for Gyutaro and later Ume), who hated her son for being born a boy because it was bad for her line of work, and abused him to make herself feel better. She fed him so little that he had to eat mice and insects to survive, and other children would bully him and throw rocks at him because he was so ugly. When Ume was born, their mother was jealous of her beauty even when she was just a baby, and once tried to cut her hair off, only being stopped by Gyutaro. When Ume turned thirteen and was training to become a courtesan, she stabbed out the eye of a samurai who tried to assault her and insulted her brother, and in retaliation, she was bound hand and foot, burned alive, and thrown into a shallow grave. She was burnt to a crisp but ''still alive'' when her brother returned home.

* And who's the one responsible for ''all'' the demons that terrorize Japan? '''''[[Characters/DemonSlayerKimetsuNoYaibaMuzanKibutsuji The Demon King, Muzan Kibutsuji]]'''''. Everything about that monster is pure nightmare fuel at its finest. The guy is a living [[TheSociopath sociopathic monster]] with a lot of mental issues. And we mean, ''a lot of issues''. From his [[HairTriggerTemper nasty temper]], [[TheNarcissist his narcissistic personality]], and his [[LackOfEmpathy strong lack of empathy and kindness towards others]], Muzan is one demon you would '''NEVER''' want to come across. Because [[AxCrazy the guy is so deranged in his mind]] and is [[EvilIsPetty just so incredibly petty in general]], he would do things you would likely or not likely expect him to do. On one hand, he might turn you into a demon. On the other hand, he would just kill you brutally. Either way, it would not be a merciful sight to witness. If you want a prime example of nightmare fuel in this series, then ''Kibutsuji'' is your lucky guy. Each folder regarding him can be found and they will ''not be pleasant to read about''.

* '''[[Characters/DemonSlayerKimetsuNoYaibaMuzanKibutsuji The Demon King, Muzan Kibutsuji]]'''. Everything about that monster is pure nightmare fuel at its finest. The guy is a living [[TheSociopath sociopathic monster]] with a lot of mental issues. And we mean, ''a lot of issues''. From his [[HairTriggerTemper nasty temper]], [[TheNarcissist his narcissistic personality]], and his [[LackOfEmpathy strong lack of empathy and kindness towards others]], Muzan is one demon you would '''NEVER''' want to come across. Because [[AxCrazy the guy is so deranged in his mind]] and is [[EvilIsPetty just so incredibly petty in general]], he would do things you would likely or not likely expect him to do. On one hand, he might turn you into a demon. On the other hand, he would just kill you brutally. Either way, it would not be a merciful sight to witness. If you want a prime example of nightmare fuel in this series, then ''Kibutsuji'' is your lucky guy. Each folder regarding him can be found and they will ''not be pleasant to read about''.

* The entire premise of the manga is that evil demons are inhabiting and invading Japan. Terrifying, monstrous, bloodthirsty demons that come out during the night in search of human prey. Demons that were once human beings. They can devour you alive or turn you into a demon yourself. If you're not a Demon Slayer, you have no way to defend yourself or your family from a demon, and if you're attacked, you better pray for a quick death. If you ''become'' a demon, you are instantly filled with a primal instinct to kill and devour that will cause you to see anyone as food, including innocent bystanders and your own family members. You will also gradually lose your original personality and memories. Even the Demon Slayer Corps regularly lose many of their swordsmen to demon attacks, because they are just that powerful.

* '''[[BigBad The Demon King, Muzan Kibutsuji]]'''. Everything about that monster is pure nightmare fuel at its finest. The guy is a living [[TheSociopath sociopathic monster]] with a lot of mental issues. And we mean, ''a lot of issues''. From his [[HairTriggerTemper nasty temper]], [[TheNarcissist his narcissistic personality]], and his [[LackOfEmpathy strong lack of empathy and kindness towards others]], Muzan is one demon you would '''NEVER''' want to come across. Because [[AxCrazy the guy is so deranged in his mind]] and is [[EvilIsPetty just so incredibly petty in general]], he would do things you would likely or not likely expect him to do. On one hand, he might turn you into a demon. On the other hand, he would just kill you brutally. Either way, it would not be a merciful sight to witness. If you want a prime example of nightmare fuel in this series, then ''Kibutsuji'' is your lucky guy. Each folder regarding him can be found and they will ''not be pleasant to read about''.

** As a side note, as Tanjiro is attempting to decapitate Hantengu, the latter lets out a [[HellIsThatNoise horrific screech that sounds like a mixture of a demon's signature raspy squeal and grinding metal]].

* Chapter 125: While Mitsuri was holding off Zohakuten, Tanjiro, Nezuko, and Genya finds Hantengu's main body and Tanjiro goes once again to deliver the decapitation of the cowardly demon. However, to Tanjiro's (as well as the audience's) shock, Hantengu unexpectedly grows into a larger body and brutally chokes Tanjiro, all while screaming in rage on how he's truly innocent and why Tanjiro couldn't see that. If it weren't for Genya and Nezuko, Tanjiro would slowly die a brutal death by the hands of Hantengu's giant clone that is Urami, the personification of Hantengu's resentment.

*** The scariest part about this is that Hantengu had lied so many times that he even forgot his own name. He's been lying for so long that he can't remember his real name, mainly because he kept creating fake identities to commit his atrocities. This showcases just how truly insane Hantengu truly was as an human.

* Chapter 116: After finding the main body of Hantengu, Tanjiro uses his Hinokami Kagura to decapitate the cowardly demon. At first, it seems to go well. Until Tanjiro suddenly feels the presence of a demon, whose body is covered in shadows closing in on him, while he's trying to finish off Hantengu. The demon then uses his [[DrumsOfWar drum]] to summon wood dragons to attack Tanjiro, and the boy gets nearly killed, but was luckily saved by Nezuko. After getting to safe distance, Tanjiro and his group comes face-to-face with the sixth clone of Hantengu: '''Zohakuten''', the personification of [[PowerofHate Hantengu's hatred]], the four emotion clones fused into one. And the worst part is that he's also credited as Hantengu's '''strongest clone''', meaning he's far more dangerous than his other four clones.

** Muichiro manages to slice off the demon's head, so victory, right? Well, it was greatly doubtful, since A. Hantengu was rather defeated too quickly, which quickly rose suspicion. B. Tanjiro notes that despite slicing off an Upper Rank demon's head off, they don't usually die that easily, as best seen with Daki, which quickly cause Tanjiro to warn Muichiro that something was up. His (As well as the audience's) deduction were proven correct, as Hantengu suddenly split into two, with one regenerating his head back, while the other gain a body. Muichiro goes to attack one, but he suddenly lifts a leaf-fan and lifts it down at Muichiro. It stops for a quick second, before Muichiro is [[BlowYouAway suddenly blown away from a strong gust of wind projected by the leaf-fan]]. After the wind, Tanjiro and Nezuko comes to face-to-face with Hantengu's clones: [[HairTriggerTemper Sekido]], the personification of Hantengu's anger and [[BloodKnight Karaku]], the personification of Hantengu's relaxed.

** Despite [[BigDamnHeroes Genya's rescue]], he unknowingly made the mistake of decapitating Sekido and Karaku, since they again split into two more demon clones: [[TheEeyore Aizetsu]], the personification of Hantengu's sorrow and [[BloodKnight Urogi]], the personification of Hantengu's joy, [[PowerGivesYouWings who also has wings on his back]], allowing him to fly. This pretty much made the [[FromBadtoWorse fight against Hantengu far more harder]], as they are growing increasingly stronger than ever, with Tanjiro, Nezuko, and Genya getting ton of damages from the clones.

** And how exactly did Zohakuten came to be? Well, it was because of [[TheLeader Sekido]], who fuses with Karaku, Urogai, and Aizetsu to become Zohakuten. The method of doing so? By '''FORCEFULLY''' [[ForcedTransformation absorbing them]]. Karaku's and Urogai's horrified expressions and Aizetsu [[OhCrap attempting to protest]] further supports the fact Sekido fuses with his other three clones into Zohakuten without their consent.
** Zohakuten in general is a terrifying demon to witness. He has the form of a child, and is clearly like [[HairTriggerTemper Sekido]], angered by those who dare hurt his main body's "weak self" and can give out a [[DeathGlare intense death glare]] that it paralyzes Tanjiro and his group in fear. And the worse part is that he has all of [[AllYourPowersCombined his four clones's abilities]], possibly to a greater extent: Sekido's [[ShockandAwe electricity]], Karaku's [[BlowYouAway gust of wind]], Urogai's [[SuperScream sonic scream]], and Aizetsu's [[RazorWind piercing blows of air]], making him an even harder opponent than his other four clones.

* The entire premise of the manga is that evil demons are inhabiting and invading Japan. Terrifying, monstrous, bloodthirsty demons that come out during the night in search of human prey. Demons that were once human beings. They can devour you alive or turn you into a demon yourself. If you're not a Demon Slayer, you have no way to defend yourself or your family from a demon, and if you're attacked, you better pray for a quick death. If you ''become'' a demon, you are instantly filled with a primal instinct to kill and devour that will cause you to see anyone as food, including innocent bystanders and your family members. You will also gradually lose your original personality and memories. Even the Demon Slayer Corps regularly lose many of their swordsmen to demon attacks, because they are just that powerful.

* The entire premise of the manga is that evil demons are inhabiting and invading Japan. Terrifying, monstrous, bloodthirsty demons that come out during the night in search of human prey. Demons that were once human beings. They can devour you alive or turn you into a demon yourself. If you're not a Demon Slayer, you have no way to defend yourself or your family from a demon, and if you're attacked, you better pray for a quick death. If you ''become'' a demon, you are instantly filled with a primal instinct to kill and devour that will cause you to see anyone as food, even your own family members. You will also gradually lose your original personality and memories. Even the Demon Slayer Corps regularly lose many of their swordsmen to demon attacks, because they are just that powerful.

* The entire premise of the manga is that evil demons are inhabiting and invading Japan. Terrifying, monstrous, bloodthirsty demons that come out during the night in search of human prey. Demons that were once human beings. They can devour you alive or turn you into a demon yourself. If you're not a Demon Slayer, you have no way to defend yourself or your family from a demon, and if you're attacked, you better pray for a quick death. If you ''become'' a demon, you are instantly filled with a primal instinct to kill and could even turn on your own family members, and will gradually lose your original personality and memories. Even the Demon Slayer Corps regularly lose many of their swordsmen to demon attacks, because they are just that powerful.

Chapter 106: While not as scary as [[MadArtist Gyokko]], [[DirtyCoward Hantengu (Upper Moon 4)]] is nevertheless a very creepy and admittedly odd demon. For starters, he takes the form of a elderly man, who's always crying and shivering in fear, even to the smallest of things, and he also has a [[FacialHorror big bulge on his forehead]], further adding the creepiness of his appearance. This would rather confuse the audience on why he's even the fourth-ranked upper demon in the first place, considering that his appearance and cowardly personality in general makes him look like a weak demon. That is until until he and Gyokko attacks the swordsmith village that he shows the audience why he's [[StrongerThanTheyLook Upper Moon 4 in the first place]].

** Despite [[BigDamnHeroes Genya's rescue]], he unfortunately made the mistake of decapitating Sekido and Karaku, since they again split into two more demon clones: [[PerpetualFrowner Aizetsu]], the personification of Hantengu's sorrow and [[BloodKnight Urogi]], the personification of Hantengu's joy, [[PowerGivesYouWings who also has wings on his back]], allowing him to fly. This pretty much made the [[FromBadtoWorse fight against Hantengu far more harder]], as they are growing increasingly stronger than ever, with Tanjiro, Nezuko, and Genya getting ton of damages from the clones.

*** Urogai's [[SuperScream Blood Demon Art]] allows him to to generate and scream powerful sound waves from his mouth. When used, the power is so strong that it made Tanjiro bleed from both his nose and ears, stunning him momentarily. He can also use utilize the demon art with his flesh, as best seen when he uses his flesh to turn his severed leg into a mouth to scream waves at Tanjiro again. Just like Karaku, thanks to Urogai's [[BloodKnight thrill of battle]], he's just as bad as his other fellow clones.
* Chapter 111: Gyokko (Upper Moon 5) looks very unsettling, looking like a mixture of a humanoid figure with some fish parts, who lives inside of a ceramic pot and has the position of his eyes and mouth(s) exchanged, but the worst part of him is his twisted personality, being a MadArtist who gets very upset if people don't appreciate his macabre "art". One of the most horrid examples is a "work of art" that he shows to Tokitou, showing several swordsmiths having their bodies stitched together in a terrifying fashion, with them [[AndIMustScream still being alive after the process]], as shown when Gyokko stabs one of them with a sword and he screams in agony. If that is not enough, his main ability is the power to summon some strange demonic fish-like beings that look straight of a work of Creator/JunjiIto.

** Zohakuten in general is a terrifying demon to witness. He has the form of a child, and is clearly like [[HairTriggerTemper Sekido]], angered by those who dare hurt his main body's "weak self" and can give out a [[DeathGlare intense death glare]] that it paralyzes Tanjiro and his group in fear. And the worse part is that he has all of [[AllYourPowersCombined his four clones's abilities]]: Sekido's [[ShockandAwe electricity]], Karaku's [[BlowYouAway gust of wind]], Urogai's [[SuperScream sonic scream]], and Aizetsu's [[RazorWind piercing blows of air]], making him an even harder opponent than his other four clones.

* Chapter 85: Daki's brother Gyutaro emerging, nay, growing out of his sister's back like a tumor.

** Gyokko uses his Blood Demon Art to imprison Muichiro in a water basin to suffocate.

** The way [[VillainousBreakdown the demon panics and breaks, repeatedly]], as soon as Tanjiro asks him information about Muzan. It shows that the majority of the demon race greatly fears the man very much, and those who know of him and see his face? They have to keep quiet or something terrible happens to them.

** The worst part? Doing this is ''completely pointless''. His greatest threat, The Demon Slayer Corps, already knows his name, and there's no indication the majority of demons even know anything about Muzan's abilities and weaknesses that would be worth divulging. Muzan is just ''so'' impossibly paranoid and so completely uncaring about the lives of his servants that he'd rather they all die in horrible agony than risk giving his enemies the slightest possible hint of how to stop him.

* Chapter 116: After finding the main body of Hantengu, Tanjiro uses his Hinokami Kagura to decapitate the cowardly demon. At first, it seems to go well. Until Tanjiro suddenly feels the presence of a demon, whose body is covered in shadows closing in on him, while he's trying to finish off Hantengu. The demon then uses his [[DrumsOfWar drum]] to summon wood dragons to attack Tanjiro, and the boy gets nearly killed, but was luckily saved by Nezuko. After getting to safe distance, Tanjiro and his group comes face-to-face with the sixth clone of Hantengu: '''Zohakuten''', the personification of [[PowerofHate Hantengu's hatred]], fuse by the four emotion clones into one. And the worst part is that he's also credited as Hantengu's '''strongest clone''', meaning he's far more dangerous than his other four clones.

** The way Hantengu enters the room where Tanjiro, Nezuko, and the Mist Hashira, Muichiro Tokito are in. [[StealthExpert He simply just slides the door open and creepily crawls in]], all while shivering and whimpering in fear, with tears in his eyes. The creepy part about this is that Tanjiro and Muichiro didn't even seem to notice him until he entered the room. Tanjiro, who's noted to have an [[TheNoseKnows incredible sense of smell]], couldn't smelt the scent of Hantengu until he enters inside the room. This further enhances the danger Hantengu actually represents despite his appearance and cowardly persona.

Chapter 106: While not as scary as [[MadArtist Gyokko]], [[DirtyCoward Hantengu (Upper Moon 4)]] is nevertheless a very creepy and admittedly odd demon. For starters, he takes the form of a elderly man, who's always crying and shivering in fear, even to the smallest of things, and he also has a [[FacialHorror big bulge on his forehead]], further adding the creepiness of his appearance. This would rather confuse the audience on why he's even the fourth-ranked upper demon in the first place, considering that his appearance and cowardly personality in general makes him look like a weak demon. That is until until he and Gyokko attacks the swordsmith village that he shows the audience why he's [[StrongerThanTheyLooK Upper Moon 4 in the first place]].

** Despite [[BigDamnHeroes Genya's rescue]], he unfortunately made the mistake of decapitating Sekido and Karaku, since they again split into two more demon clones: [[PerpetualFrowner Aizetsu]], the personification of Hantengu's sorrow and [[BloodKnight Urogi]], the personification of Hantengu's joy, [[PowerGivesYouWings who also has wings on his back]], allowing him to fly. This pretty much the [[FromBadtoWorse fight against Hantengu far more harder]], as they are growing increasingly stronger than ever, with Tanjiro, Nezuko, and Genya getting ton of damages from the clones.