History WebAnimation / Underverse

* ScrewTheRulesTheyBrokeThemFirst: Error and Ink made a truce before the series that neither of them would create or destroy [=AUs=]. When Error believes that Ink's agreement with [=XGaster=] is violating the truce, he decides to [[spoiler:[=destroy the entire doodle sphere right in front of Ink and the other characters=]]].

* ScrewTheRulesTheyBrokeThemFirst: Error and Ink made a truce before the series that neither of them would create or destroy AUs. When Error believes that Ink’s agreement with XGaster is violating the truce, he decides to [[spoiler:[=destroy the entire doodle sphere right in front of Ink and the other characters=]]].

* WhatTheHellAreYou: Fell Sans' reaction word for word when Cross survives being hit by his surprise attack.

* BigBadEnsemble: There's a whole slew of antagonists competing for the BigBad title in the first season, the most notable being [[TheHeavy [=XTale Chara=]/X-Event Chara]], [[TheManBehindTheMan Nightmare Sans]], and [[MarionetteMaster Error Sans]]. X-Event Chara and Nightmare form a tenuous BigBadDuumvirate while Error is looking to wipe out the "anomalies" from the Multiverse, which are the protagonists. It isn't until the season finale where we finally have a solid BigBad in the form of [[GreaterScopeVillain [=XGaster=]]], who shows up the entire ensemble to become the main villain of the second season.

* BloodlessCarnage: [[spoiler:Mettatton's death]] would be far, ''far'' more graphic if he wasn't [[spoiler:a robot]]. This doesn't make his dismemberment any less horrific.

** [=XGaster=] starts melting in XTALE X from overusing Determination, eventually reducing him from a fairly good-looking skeleton to a melting legless demonic mess. [[spoiler:His revival in 0.4 stops the melting part, but he still has no legs, replaced with glitches, and he looks more like a clawed fanged demon sith a SlasherSmile than a monster.]]

* NoAntagonist: Even though there are quite a few candidates that could pass as the true antagonist, [[WordOfGod Jakei]] has explicitly stated that there is no real antagonist, thus many have different opinions on who's the bad guy in the story.

* TheCorruption: The only way to describe how [=XGaster=]'s code affects his surroundings. Everything he or his puppets attack -- buildings, objects, even people - transform into his purple colour pallette, and it's implied that he's somehow... affectiong their code or something.

* CloningBlues: Cross and [=XGaster=] both express different shades of this: Cross wonders if his life is worth anything considering he is a copy, while [=XGaster=] asks Core Frisk who decided he is the fake and that the others are better.

* TheCorruption: The only way to describe how [=XGaster=]'s code affects his surroundings. Everything he or his puppets attack - buildings, objects, even people - transform into his purple colour pallette, and it's implied that he's somehow... affectiong their code or something.

* AllergicToEvil: Dream, since he can only use his powers in a positive environment.

* [[https://www.youtube.com/watch?v=Qt8kN0fsKu0&list=WL&index=5&t=0s XTALE VI]]: The sixth iteration of X-Tale [=XGaster=] created. Focuses on Chara. Marks the beginning of the X-Event experiment.

* [[https://m.youtube.com/watch?v=q0VFZpEYgkE Underverse 0.2]]: All hell breaks out in the Underfell universe, as Underfell Sans and Cross fight for the right to Snowdin.
* [[https://m.youtube.com/watch?v=Rf8MtX0vsCo Underverse Xtra Scene 1]]: Shows the events after Underverse 0.2, in which Error confronts Ink regarding the X-Event.
* [[https://m.youtube.com/watch?v=QRBOCpuT2r4 Underverse 0.3 Part 1]]: Cross heads for the Underswap universe next, but after an encounter with Ink's group, things take a turn for the worse.
* [[https://youtu.be/MA_o7lEs6cc Underverse 0.3 Part 2]]: X-Event Chara demonstrates the power to OVERWRITE to the Underswap gang as Ink fights to protect a mysterious vial.
* [[https://youtu.be/swlSB020gyE Underverse Xtra Scene 2]]: In a very unpleasant manner, Error discovers the secret of the X-Event.
* [[https://m.youtube.com/watch?v=__T7CqkYKTE Underverse 0.4]]: As everyone settles from the previous episodes, an even greater threat than Cross/X-Event Chara makes itself known to the universe, leaving the fate of the multiverse at an even greater risk than ever before.

* AttentionWhore: [=Error=] [[spoiler: in 0.7 Part 1. He is visibly enraged that even after destroying the multiverse, nobody is paying attention to him, everyone is focused on [=XGaster=]'s game.]]
* BaitAndSwitch: [[spoiler: ''Owners'' starts out with Flowey talking to someone and correctly deducing that they are "not happy with what [they've] done". At first it seems like he's talking to Frisk/Chara after a genocide run - only for the very next few scenes to reveal that it was actually ''Sans'' he was talking to and that Sans and Frisk/Chara have teamed up to kill him.]]

** [[spoiler: While Season 2 does see [=XGaster=] taking on a more active role, Nightmare is far from out of the picture, and seems to have his own plans for [=XGaster’s=] “perfect universe”.]]

* BloodKnight: X-Event Chara. He enjoys fighting the Sanses and approaches their confrontations with sadistic glee. [[spoiler: Until he's significantly depowered by Nightmare.]]

** The mysterious vial Ink seems keen on protecting and keeping secret, first appearing in 0.3 Part 1. [[spoiler: 0.4 reveals it to be half of [=XGaster's=] soul, which Ink proceeds to set free, allowing [=XGaster=] to come back.]]
** The artwork for [[https://m.youtube.com/watch?v=TkZIiwi-s5s&t=2s Fresh's theme ver.3]] has a purple gift box in the background. [[spoiler:In 0.5, [=XGaster=] makes]] that very same gift box at [[spoiler:Ink's request]]. It also crosses with {{Foreshadowing}}, as in XTRA SCENE 2, Fresh says that [[spoiler:Ink promised him something nice]]. In 0.7 Part 1, this [[spoiler:becomes the catalyst for Fresh!Ink.]]

** In XTRA SCENE 2, Fresh mentions that [[spoiler:Ink]] promised him something nice out of his game. In addition, the [[https://m.youtube.com/watch?v=TkZIiwi-s5s&t=2s artwork for Fresh's theme]] features a purple gift box. That box shows up in 0.5, [[spoiler:made by [=XGaster=] at Ink's request.]]

** X-Event Chara and X-Event Frisk started out as purely heroic characters who disapproved of their father's abysmal treatment of their friends in the [=XTALE=] timelines and made it their goal to stop him, so that everyone could live free of his influence. [[spoiler:His constant torture and mistreatment slowly whittled away what sanity and altruism they had, leading to their sincere desire to free their friends to become a need to make sure that [=XGaster=] dies so that they can take control.]]

** In 0.5, [[spoiler: [=XGaster=] forces his will on every single [=XTale=] cast member (except Cross and [=XChara=]), leaving them to cry for help but unable to express their words. His control is so good that he can speak ''through'' them.]]

** The entirety of season 1. Ink gathers a group of Sanses to stop Cross and X-Chara from destroying the multiverse. In ''0.3, part 1'', they manage to stop Cross, but then X-Chara takes over as the BigBad. [[spoiler: Even worse, in ''0.4'' it's revealed that Ink is secretly working for [=XGaster=], the ''actual'' Big Bad. The multiverse ends up destroyed in the ensuing scuffle and Underswap- and Underfell-Sans are killed. [=XGaster=] reclaims the missing half of his soul and prepares to conquer the main universe.]]

** Basically all the Sanses and X-Event Chara, thought it's kinda {{Justified}} as well as {{Subverted}}, since X-Event Chara is [[spoiler: Really700YearsOld and]] an AxCrazy RealityWarper.
** Nightmare at the end of 0.3 part 2 as he [[spoiler: stabs Underswap Chara]].