History YMMV / WhatIfS1E8WhatIfUltronWon

* WTHCastingAgency: While most of the recasted characters for this show have been accepted by fans, Creator/RossMarquand as Ultron has proven to be a little more contentious. Mostly, it's due to the fact that his voice bears little resemblance to Creator/JamesSpader's take on the character from ''Age of Ultron'', a performance that was going to be a ToughActToFollow regardless.

* AssPull: Thanos somehow managing to get the rest of the Infinity Stones. As noted on the main page, the sequence of events that led to Thanos claiming the stones would not have matched up with the canon up till that point (Gamora still being alive despite the fact that Thanos would have needed her to know where the Soul Stone is and get it, Asgard and Xandar still being intact,[[note]]Surtur destroyed the former during ''Film/ThorRagnarok'' while Thanos attacked the latter right before the start of ''Infinity War'' to obtain the Power Stone[[/note]] no word of Thanos being on Earth before despite the fact that he would’ve needed to come to the planet to collect the Time Stone, etc...) While it can be justified due to multiverse theory, some felt it was just a contrived way for Ultron to get the rest of the Infinity Stones as quickly as possible.

* AuthorsSavingThrow:
** For those disappointed with how little Ultron was ultimately used in the MCU, [[SuperheroMovieVillainsDie having been introduced then killed off in the span of]] [[Film/AvengersAgeOfUltron one movie]], this episode brings him to the prominence and threat levels shown by his comics counterpart. With one minor deviation, he was able to completely dominate the Earth and eventually the universe, and grow to become a multiversal threat. Additionally, his "Infinity Ultron" design harkens closer to his iconic Jack-O' Lantern face, a design many fans preferred over his live-action appearance.
** Clint making a HeroicSacrifice on Natasha's behalf satisfied many fans who were rubbed the wrong way with Natasha's death in ''Endgame''.
** A lot of fans weren't happy that Vision spent much of ''Infinity War'' undergoing TheWorfEffect, thus making himself dead weight for most of the confrontation against Thanos. Ultron demonstrates how powerful Vision could've been in the Battle of Wakanda had Corvus Glaive not stabbed him by one-shotting Thanos himself the second he appears in this episode.
** Many fans of Arnim Zola didn't like how the character was seemingly KilledOffForReal in the middle of ''Film/CaptainAmericaTheWinterSoldier'', especially due to him being a powerful recurring antagonist in the comics. This episode reveals that Arnim created several copies of his consciousness for HYDRA to use, one of which was stored in the KGB archives. Not only does this allow Zola to reappear in this episode's reality, but it also opens up an opportunity for him to potentially return in the MCU's Sacred Timeline down the road.
** The Infinity Stones also get more of a spectacular showcase after being relatively underutilized. Infinity Ultron really shows the kind of cosmic reality warping that can be done with them all together without burning out the user.
** Quite a few followers of the MCU have disliked how the franchise often leans towards more of a comedic side, [[{{Bathos}} even when the situation isn't remotely appropriate]] for quips and jokes. This episode somewhat lampshades that problem by having Clint complain about Natasha trying to lighten up the mood in the KGB headquarters despite having just lost everyone in the world around them, including his family.

* CompleteMonster: ** "[[Recap/WhatIfS1E8WhatIfUltronWon What If...Ultron Won?]]" & "[[Recap/WhatIfS1E9WhatIfTheWatcherBrokeHisOath What If...The Watcher Broke His Oath?]]": [[Characters/MCUUltron Infinity Ultron]] decides "peace" means [[OmnicidalManiac the eradication of all life]]. Wiping out all of humanity with [[NukeEm a nuclear apocalypse]], Ultron kills [[Characters/MCUThanos Thanos]] and directs his attention to the systematic genocide of all other life in the universe. Once finished, Ultron [[EvilLearnsOfOutsideContext recognizes the existence of the Multiverse itself]] and, armed with the Infinity Stones, attempts to completely purge every single universe of life for his own twisted aims.

* CompleteMonster: [[Characters/MCUUltron Infinity Ultron]] decides "peace" means [[OmnicidalManiac the eradication of all life]]. Wiping out all of humankind with [[NukeEm a nuclear apocalypse]], Ultron kills [[Characters/MCUThanos Thanos]] and directs his attention to systematic genocide of all life in the universe. Once finished, Ultron [[EvilLearnsOfOutsideContext recognizes the existence of the Multiverse itself]] and, armed with the Infinity Stones, attempts to completely purge every single universe of life for his own twisted aims.

* {{Narm}}: Thanos' death, putting aside the intended anticlimactic nature, is too quick and cartoony as Ultron bisects him in a second.

* CompleteMonster: [[Characters/MCUUltron Infinity Ultron]] decides "peace" means [[OmnicidalManiac the eradication of all life]]. [[KillAllHumans Wiping out all of humankind]] with a [[NukeEm nuclear apocalypse]], Ultron kills [[Characters/MCUThanos Thanos]] and directs his attention to systematic genocide of all life in the universe. Once finished, Ultron recognizes the existence of the Multiverse itself and, armed with the Infinity Stones, attempts to completely purge every single universe of life for his own twisted aims.