History NightmareFuel / YuGiOhGX

* Trueman's and Darkness' (the one from the last arc) monsters could qualify. Along with Trueman and Darkness themselves of course...
** Dark Archetype is a revolting creature just next-door to Relinquished in terms of weird. The Dark Psycho Eye Trueman summons during his duel with O'Brien using it is also pretty bad...since just when O'Brien destroys ''that'' monster, it opens up an enormous eye in its chest, which is the trigger for Trueman to MindRape O'Brien throughout their duel.

** Darkness Bramble, which bursts through Darkness' chest, Darkness Outsider, which is a clown which opens its face to spear things with its brain tentacles and bring them over to its master's field, and Darkness Neosphere especially.
** Darkness himself, perhaps one of the most visceral villains next to the original series' Zorc. He appears as a massive goat-headed skeleton with five wings to serve as his duel disk, and the way his cards manifest is ''always'' in a flash of darkness deliberately inverting the normal flash of golden light signifying that a card is played, which helps cement him as the EldritchAbomination that he is ...which is ''solidified'' when we get his [[BlueAndOrangeMorality personality]]. Unlike the CardCarryingVillain nature of his predecessor [[Anime/YuGiOh Zorc]] and the later [[Anime/YuGiOhZEXAL Don Thousand]], the WellIntentionedExtremist that was [[Anime/YuGiOh5Ds Z-ONE]], and even the OmnicidalManiac known as [[Anime/YuGiOhArcV Z-ARC]], Darkness is disturbing in that he's less a person than a [[SentientCosmicForce force of nature]], demonstrated all the more by his own card being a ''field spell'' rather than a monster. A ''world'' of negativity that's both sentient and actively antagonistic to humanity, who believes that his AssimilationPlot is a 100% natural course of action and to be expected after all of the prior arcs created enough dimensional disturbances for him to appear. He's always calm when speaking to Judai (minus his ranting and speeches about this philosophy, but even then, his echoing voice lends those a creepy vibe), and fully believes that humanity will fall into despair after he's defeated and that he will return. Why does he believe this? Well... the following scenes reveal that ''he is correct'' in some way, [[Anime/YuGiOh5Ds concerning each of the]] [[Anime/YuGiOhZEXAL three series]] [[Anime/YuGiOhArcV coming after...]]
*** One of these scenes is a ''[[SarcasmMode charming]]'' sight of a destroyed Duel Academy that he claims is the future of the world. While dismissed at the time, later series reveal that no, this ''was'' the future of the world, to some degree. That ruined future? Very similar to the world after the Meklord Emperor Genocide in 5Ds, aka the SequelSeries to GX. Darkness ''knew'' about it.
*** Another scene has him describe the universe as having started from a card, which in ZEXAL is revealed to not be a metaphor, it is quite literally true: The Numeron Code was a powerful card that played a role in the creation of the universe. While ZEXAL's relation to 5Ds continuity-wise is unknown, it does in fact, take place after GX. Meaning that Darkness ''knew about a powerful artifact that only ancient inter-dimensional aliens should have had knowledge of''.

*** All of the above gives Darkness this feeling of omnipresence, that he is always there, that his influence continues to persist. His claims that he will always come back? Those may very well be fully vindicated if he truly knew about all of these catastrophes, which continues to increase the scope and dread that he brings about. Even though Judai defeated him, there's a very good chance that yes, he ''will'' return one day, and his claims that he'll succeed amidst Judai believing that other duelists will ensure that he never resurrects might have more weight to them.
* The World of Darkness. An alternate dimension where people experience their worst fears, doubts and regrets until they cannot take it any more and give up their individuality willingly. For example, Alexis/Asuka fears she would not be a good teacher, so she stops trying and gives up her dream. Thank God Jaden/Judai is able to snap her and everyone else out of it and free them all.

*** His duel against O'Brien is a candidate for the most disturbing in the franchise. [[ShapeshifterGuiltTrip Taking the form of O'Brien's father]], Trueman proceeds to torment him by bringing up an incident from his childhood where his parents got caught up in a car crash and he could only save one in time. While it's eventually revealed that O'Brien's father regained consciousness in time to save his mother too, O'Brien has never forgiven himself for cynically choosing to save his father because O'Brien felt that he was the one who could best take care of him, something Trueman mercilessly exploits to screw with O'Brien's head and bait him into making a fatal mistake at the last moment. Cue Trueman's trap card and O'Brien's loss, as the flames of their monsters and the flames in O'Brien's memory of the burning car blend together as one. Worse, you can see a horrified O'Brien ''[[OhCrap realise]]'' said mistake just a second too late, in a perfect example of how badly you can slip up under psychological warfare.
*** Even the normally immune Kenzan falls after Trueman, disguised as Sorano, shows him a vision of his past life as a dinosaur gruesomely devouring another, whose bone would be integrated into Kenzan's body in the present day.

* The Facial expressions pulled by Saiou when The Light of Ruin fully possesses him are worthy of rivalling Yami Marik's facial distortions.
* Yubel. Just, Yubel. A ''batshit insane'' stalker that considers sharing of all of their painful feelings, most notably pain. Judai is stalked by a monster that is not only possessive to the point where they try to kill anybody else that gets close to him, but ''genuinely'' considers making his life a living hell. The fact that they looks like Yami Marik and Yami Bakura's love child doesn't do anything to lower the nightmare factor.
** That living hell consists of breaking him down mentally from the shadows until his mind literally splits by making him believe Johan is dead, turning his friends against him and making him believe he murdered them, all to trigger his SuperPoweredEvilSide who then goes on a genocidal rampage.
** Worst of all is that Yubel gets away scotfree. Considering how much shit they put Judai through up until this point and how much he hated them for it, it's very questionable if actually Judai had any choice.
** What they do to Johan and his family is pretty horrifying. The show doesn't go into much detail but what little we get is bad enough. They corrupt the Crystal Beasts and Rainbow Dragon into evil imitations of themselves - implied to be fully conscious too - and then rip Johan's soul out of his body to imprison him in a prison of anguish, in their own words. They then use his body to hurt Judai as much as possible, punish the Crystal Beasts for daring to speak with Judai, and even try to trick Judai into thinking Johan has turned evil all because Johan dared be important to Judai.
* There's something inherently disturbing about seeing Judai/Jaden, the happy-go-lucky protagonist, [[BreakTheCutie losing everything]] [[FaceHeelTurn before turning evil.]]
* Episode 45 and 46 give us the [[SarcasmMode lovely]] image of Daitokuji's mummified corpse. Have fun with that. Oh, and his homunculus body has this nasty habit of cracking and falling apart alive too.
* Episode 65. Every single element of the Underground itself is incredibly disturbing to begin with (ElectricTorture as entertainment for masked spectators, cage matches, the implication that duelists have ''died'' after losing there, etc). We watch Ryo, who is ''already'' in the middle of a [[DespairEventHorizon mental crisis]], be mocked and tortured until [[FreakOut his mind snaps]] and he [[NoKillLikeOverkill obliterates Mad Dog in a brutal rage]]. Mad Dog gets blasted right through the steel bars of the cage and just lies there, immobile and ''smoking''. He might be dead. He's unconscious and horribly injured at the very least. Ryo's ''terrifying'' SlasherSmile at the end when he's back in the Pro League ends the episode on one hell of a nightmarish, ominous note. A little more FridgeHorror about how bad the ElectricTorture must be in the Underground: this character, who barely made any sound when hit directly with a 4000-point attack in a shadow game, is ''screaming'' in agony after a loss of only a few ''hundred'' Life Points.

** Titan however returns as the 6th Seven Stars and he becomes far more sadistic than he was before as in Asuka/Alexis's duel against him he clearly enjoyed tormenting her both physically and mentally, even openly says that seeing her in pain brings him joy as a shadow duelist.

* Amon, in the later parts of his arc, does some majorly disturbing things. Watching Echo insist on sacrificing herself for him and him accepting so easily is horrifying.

* Episode 98: Destiny Hero Bloo-D and everything about it. Not only are the monster itself and its effect disturbing to look at, but DD has been using it to trap ''[[AndIMustScream human souls]]'', including Edo's father. It's actually worse in the dub, where Aster's father just [[NeverFoundTheBody disappeared]] and Aster only finds out now that this is what became of him.

* Being a vampiress Camilla/Camula ''thrives'' off of this! While her backstory makes her [[JerkassWoobie somewhat sympathetic]] she's still an evil vampire who with every duel won, steals a soul she plans to use to resurrect a member of her vampire race. The [[NightmareFace faces]] she makes during her duels do ''not'' help!
** Add to that, her signature card Illusion Gate requires the cost of someone's soul if she should lose the duel. Not her soul or even her opponent's, ''anyone she chooses'', a tactic she uses against Ryou/Zane with Shou/Syrus’ soul and nearly does against Judai/Jaden with the souls of everyone present. Thank goodness for the Shadow charm from Fubuki/Atticus!

* Yubel. Just, Yubel. A ''batshit insane'' stalker that considers love to be sharing of all feelings, most notably pain. Judai is stalked by a monster that is not only possessive to the point where they try to kill anybody else that gets close to him, but ''genuinely'' considers making his life a living hell a sign of love. The fact that they looks like Yami Marik and Yami Bakura's love child doesn't do anything to lower the nightmare factor.

** Worst of all is that Yubel gets away scotfree because Judai ends up giving them exactly what they wanted by fusing their souls together. Considering how much shit they put Judai through up until this point and how much he hated them for it, it's very questionable if that's actually Judai's decision or the Supreme King's influence.
** What they do to Johan and his family is pretty horrifying. The show doesn't go into much detail but what little we get is bad enough. They corrupt the Crystal Beasts and Rainbow Dragon into evil imitations of themselves - implied to be fully conscious too - and then rip Johan's soul out of his body to imprison him in a prison of anguish, in their own words. They then use his body to hurt Judai as much as possible, punish the Crystal Beasts for daring to speak with Judai, and even try to trick Judai into thinking Johan has turned evil all because Johan dared be important to Judai. Imagine just getting close to someone and then an insane stalker decides to torture you and your family for it.

* Doll Chimera takes the CreepyDoll trope and cranks it UpToEleven. It starts out as a decrepit mannequin that stands on all fours like a giant spider, and each time it's destroyed, it comes back and grows additional torsos and limbs with its own effect. At full power, it has three torsos joined at the hip, each with its own limbs and head, and the [[{{Squick}} inherent Freudian imagery]] just makes it worse.

** The above situations are just two of the cases where the victims ''fought back''. Tsutumo, who is one of the first victims of the World of Darkness, is just a young child infuriated that he can't win, which summons Trueman into his room. Who then looms over [[AdultFear the young boy menacingly]] before dragging him into the World of Darkness and assuming his form, which he then [[CreepyChild uses]] to do the same to almost everyone in Domino City except for Seto Kaiba.

** The Darkness Bramble, which bursts through Darkness' chest, Darkness Outsider, which is a clown which opens its face to spear things with its brain tentacles and bring them over to its master's field, and Darkness Neosphere especially.

* Yubel. Just, Yubel. A ''batshit insane'' stalker that considers love to be sharing of all feelings, most notably pain. Judai is stalked by a monster that is not only possessive to the point where they try to kill anybody else that gets close to him, but ''genuinely'' considers making his life a living hell a sign of love. The fact that [[{{Hermaphrodite}} they]] looks like Yami Marik and Yami Bakura's love child doesn't do anything to lower the nightmare factor.

*** His duel against O'Brien is a candidate for the most disturbing in the franchise. [[ShapeshifterGuiltTrip Taking the form of O'Brien's father]], Trueman proceeds to torment him by bringing up an incident from his childhood where his parents got caught up in a car crash and he could only save one in time. While it's eventually revealed that O'Brien's father regained consciousness up in time to save his mother too, O'Brien has never forgiven himself for cynically choosing to save his father because O'Brien felt that he was the one who could best take care of him, something Trueman mercilessly evokes to torture O'Brien into making a fatal mistake at the duel's last moment. Cue Trueman's trap card and O'Brien's loss, as the flames of their monsters and the flames in O'Brien's memory of the burning car blend together as one. Worse, you can see a horrified O'Brien ''[[OhCrap realise]]'' said mistake just a second too late, in a perfect example of how badly you can slip up when someone is messing with your head.

** Being a vampiress Camilla/Camula ''thrives'' off of this! While her backstory makes her [[JerkassWoobie somewhat sympathetic]] she's still an evil vampire who with every duel won, steals a soul she plans to use to resurrect a member of her vampire race. The [[NightmareFace faces]] she makes during her duels do ''not'' help!
*** Add to that, her signature card Illusion Gate requires the cost of someone's soul if she should lose the duel. Not her soul or even her opponent's, ''anyone she chooses'', a tactic she uses against Ryou/Zane with Shou/Syrus’ soul and nearly does against Judai/Jaden with the souls of everyone present. Thank goodness for the Shadow charm from Fubuki/Atticus!

** Darkness himself, perhaps one of the most visceral villains next to the original series' Zorc. He appears as a massive goat-headed skeleton with five wings to serve as his duel disk, and the way his cards manifest is ''always'' in a flash of darkness deliberately inverting the normal flash of golden light signifying that a card is played, which helps cement him as the EldritchAbomination that he is ...which is ''solidified'' when we get his [[BlueAndOrangeMorality personality]]. Unlike the CardCarryingVillain nature of his predecessor [[Anime/YuGiOh Zorc]] and the later [[Anime/YuGiOhZEXAL Don Thousand]], the WellIntentionedExtremist that was [[Anime/YuGiOh5Ds Z-ONE]], and even the OmnicidalManiac known as [[Anime/YuGiOhArcV Z-ARC]], Darkness is disturbing in that he's less a person than a force of nature, demonstrated all the more by his own card being a ''field spell'' rather than a monster. A ''world'' of negativity that's both sentient and actively antagonistic to humanity, who believes that his AssimilationPlot is a 100% natural course of action and to be expected after all of the prior arcs created enough dimensional disturbances for him to appear. He's always calm when speaking to Judai (minus his ranting and speeches about this philosophy, but even then, his echoing voice lends those a creepy vibe), and fully believes that humanity will fall into despair after he's defeated and that he will return. Why does he believe this? Well... the following scenes reveal that ''he is correct'' in some way, [[Anime/YuGiOh5Ds concerning each of the]] [[Anime/YuGiOhZEXAL three series]] [[Anime/YuGiOhArcV coming after...]]