The conversation around Wanda Maximoff's turn to villainy in Doctor Strange in the Multiverse of Madness has been dominating the MCU fans since the film premiered. While a lot of audiences liked Elizabeth Olsen showcasing her villainous range and horror inspiration, others found her a bit lackluster with weak motives, especially after the strength of WandaVision.
Unfortunately, this is definitely an ongoing part of the MCU's villain problem, where potentially interesting bad guys end up severely disappointing viewers. From the Disney+ series such as Moon Knight to old standbys such as Thor: The Dark World, these MCU villains could have been great, but just ended up disappointing everyone.
Taskmaster - Black Widow
Taskmaster is the least disappointing out of these villains. Her character is largely different from her comic counterpart and is used more for a plot twist when it's revealed she's Antonia Dreykov. While many fans aren't a fan of Taskmaster's inclusion in the story, she does fit and work.
However, what makes Taskmaster disappointing is that she was used solely for a plot twist and was never really meant to be the real Taskmaster that fans of the comics so love. It's simply the fact that Taskmaster is used in the way they are that's disappointing. While fans haven't seen this character yet since Black Widow, it's certainly possible that she could return and maybe revise the character closer to how fans ideally wanted to see Taskmaster.
Arthur Harrow - Moon Knight
Arthur Harrow originally promised to be a unique villain with genuinely interesting motives. He had a good balance in the first couple of episodes that made it seem he wanted the greater good, yet was still willing to do questionable acts.
However, what makes Arthur an uninteresting villain ultimately comes down to the last episode. He seems devout to the ideals upheld by his goddess, but they are tossed aside when Ammit uses him as her avatar. An odd decision on both characters' parts that either made the characters brilliantly hypocritically or lazily written because it was the final episode. Ultimately, it felt flat and Arthur lost much of the complexity he had early on and the final episode ended up turning into another generic superhero fight.
Yon-Rogg - Captain Marvel
Yon-Rogg is played by the fantastic actor Jude Law and serves as the main antagonist of Captain Marvel. While he does serve as one of the most underwhelming villains in the MCU, it's possible he will have a redemption story in the upcoming The Marvels.
Yon-Rogg ultimately falls short due to his insignificance in the film. He isn't menacing nor does he serve as a great antagonist for Captain Marvel. In fact, it felt as if he was made more underwhelming simply to demonstrate how impressive Captain Marvel was. But with the MCU, if there is one thing fans love it's a villain who can push the protagonist. Yon-Rogg barely does this and basically, all of Captain Marvel's trials involving Yon-Rogg are overcome with ease.
Ronan the Accuser - Guardians of the Galaxy
Ronan serves as the main antagonist of Guardians of the Galaxy, though he is oddly pretty forgetful. With such a unique design and is, the first reference of the Kree fans always expected more from him. Even Captain Marvel was a chance for redemption, however, he only makes a small cameo.
Ronan essentially stands for what not to do as an MCU villain. Especially when compared to Ego the Living Planet, a much better villain for the Guardians who is able to push Star-Lord's character. Ronan doesn't do this for any of the Guardians and doesn't impose any terror or complexity like his character in the comics. Even his abilities are far less interesting in the films, despite Lee Pace giving the performance his all.
Kaecilius - Doctor Strange
Kaecilius is probably one of the most forgettable villains in the MCU and he's not necessarily disappointing because of his poor character, but more so that this was Mads Mikkelsen's character to play.
Mikkelsen always gives a great performance and it's a shame that a character with relatively generic writing was wasted on him. This isn't to say there isn't more hope for his character in the future, but it seems unlikely he'll ever have a role as big as he did in Doctor Strange. Kaecilius should have been a much more menacing character in the story and if Doctor Strange in the Multiverse of Madness showed fans one thing, it's how to make a villain horrifying.
Karli Morgenthau - Falcon and the Winter Soldier
Karli serves as the main villain in Falcon and the Winter Soldier and in many respects, her role feels incredibly forced. Her character collapses in the last couple of episodes of the Falcon and the Winter Soldier and it still doesn't really make sense why. She wasn't a terrible person and her motives weren't entirely wrong. She showed remorse at times for taking things too far and Sam believed he could save her. In the end, she falls deeper into the darkness and sees her death.
It felt as if John Walker would end up the villain near the end, but that doesn't end up being the case at all. There is no redemption for Karli. Given, the way she goes out and how the story concludes makes it feel like there really isn't any winner in Falcon and the Winter Soldier. Karli's character brings in many thought-provoking ideas, but her execution as a villain was incredibly poor, which makes her more of a travesty for audiences.
Ultron - Avengers: Age of Ultron
Ultron is easily one of the worst villains to touch the MCU and the same can be said about his film, Avengers: Age of Ultron which seemed to raise questions of how the MCU could have fallen so far, especially after The Avengers.
Machine villains are never easy characters to pull off and Ultron is just one of many examples of how to do it wrong. He doesn't strike fans as a very menacing character outside of him simply just causing lots of destruction. Some fans protest that Ultron isn't very interesting in the comics either, but most seem to agree that Ultron is significantly worse in the film.
Malekith - Thor: The Dark World
It is astonishing how poorly done Malekith was in The Dark World. Many fans even go as far as to say The Dark World is the worst MCU film and that Malekith is the worst villain. Thankfully, Thor's villains, for the most part, have been blessed with phenomenal performances and generally good writing, but Malekith wasn't so lucky.
Malekith lacks a menacing personality, and unique abilities, and possesses a terrible design with a large chunk of his backstory gone. One of the most surprising things that are absent from the MCU is the lack of attention to most of the realms. However, with the way the Thor films are going, it's possible that the War of the Realms arc could be adapted. This would be a perfect way to try and reintroduce Malekith (who serves as the primary villain of the arc) and give him redemption.
The Mandarin - Iron Man 3
The Mandarin has always been one of Iron Man's most threatening and iconic villains and somehow he was brutally botched in the MCU.
His initial appearances on the TV were genuinely menacing and Ben Kingsley gave a phenomenal performance, but the plot twist that he was only an actor and a fake villain with no abilities was the most incredible letdown ever. While this was a terrible event, Shang-Chi thankfully fixed this and arguably made the Mandarin better in concept than even the comics. However, the buildup in Iron Man 3 will never be forgotten by fans and he will always be one of the most disappointing villains in the MCU.
He Who Remains - Loki
In Loki, He Who Remains is played by Jonathan Majors, who is set to play Kang the Conqueror in Ant-Man and the Wasp: Quantumania. Whether or not, He Who Remains is a variant of Kang or a future version of the character in Loki remains to be seen. However, the version that premieres in the season finale of Loki is arguably the most disappointing because he just stops the show at the last minute just as things were getting truly interesting.
After all the build-up over the season and the ramping tension, He Who Remains in the season finale just stops everything to a halt. While Majors is an engaging performer, even his talent cannot stop the feeling of disappointment that this is it for the first season of Loki. Given the whole theme of Loki dealing with different versions of himself, it would have probably made more sense for He Who Remains to be a Loki. MCU fans are hoping that Kang the Conqueror will prove more interesting than He Who Remains so there can be a redemption arc here.