A handful of Marvel Comics characters are the subjects of rumors regarding who will be the villain in WandaVision. Though the show isn’t too far away from being finished and a large portion of the cast has already been confirmed, Marvel has yet to give a clear answer as to what threat Scarlet Witch (Elizabeth Olsen) and Vision (Paul Bettany) will be up against in the upcoming series.

Last seen in Avengers: Endgame, Wanda Maximoff is still reeling from the death of Vision, who was killed over the Mind Stone by Thanos (Josh Brolin) in Avengers: Infinity War. But somehow, the android Avenger will make a miraculous return in the six-episode Disney+ series, where he will reunite with Wanda, with the pair together in a strange, suburban community. For a reason that hasn’t been explained yet, their experiences there will reflect several different sitcoms from previous eras. Their story will also include other MCU characters with no clear connections to either hero, such as an adult version of Captain Marvel’s Monica Rambeau (now played by Teyonah Parris), Ant-Man and the Wasp’s Jimmy Woo (Randall Park), and Darcy Lewis (Kat Dennings) from the first two Thor films.

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As if WandaVision doesn’t have enough established MCU characters, rumors are swirling around who else will be taking part in the action. Casting reports about Evan Peters appearing on the show have led to speculation that Fox’s Quicksilver is joining the MCU. There’s also talk of other surprising MCU guest appearances, such as a potential cameo from Doctor Strange (Benedict Cumberbatch). Plus, there’s a lot of buzz surrounding one of the biggest unanswered questions about WandaVision: who is the main villain? Here are the Marvel Comics characters rumored for the role, and how good their chances are of being included.

Grim Reaper

Marvel Comics Grim Reaper

Alleged plot leaks point to the main antagonist being Grim Reaper, one of Vision’s greatest enemies. In Marvel Comics, Grim Reaper is the brother of Wonder Man, the superhero whose brain patterns were used to create Vision. During the years that Wonder Man was dead, Grim Reaper often collided with the Avengers, having convinced himself that Vision was his brother reborn in a new body. His obsession with Vision continued even after Wonder Man’s resurrection, as he still felt that there was a brotherly connection between them. He also served as the main villain in Tom King’s Vision comic, which may have at least partially inspired WandaVision, based on its suburban setting.

Though the insane and obsessive Grim Reaper would make for an interesting villain, it’s hard to imagine him fitting in WandaVision since Marvel removed Wonder Man from Vision’s origin story. Marvel could work him in regardless, but may not go in that direction considering that no setup has been offered by previous movies.

Doctor Doom

Doctor Doom And Scarlet Witch

Some rumors are suggesting that major Marvel Comics villain Doctor Doom will appear in WandaVision to set up a larger role in the MCU. Doom being incorporated in a story with Scarlet Witch makes sense, given that the two share a great deal of history in the comics. Wanda’s reality-warping powers and chaos magic have always interested Doom, so it doesn’t feel like it would be outside the realm of possibly for Doom to be pulling the strings somehow. So instead of giving him a big role, it could be revealed that Doom is the show’s real villain in a cameo appearance or in the last episode. The only problem with this idea is that Marvel may not want to introduce a character as big as Doom on the small screen. If Marvel were to use him in a Scarlet Witch story, a better solution would be Doctor Strange and the Multiverse of Madness, which could be Phase 4’s biggest film.

Related: How Old Is Scarlet Witch In The MCU? Wanda's Age Explained

Nightmare

An image of Nightmare sitting in the chair in the Marvel Comics

In the comic books, one of Doctor Strange’s most powerful foes is Nightmare, an evil entity who can enter people’s dreams. Nightmare draws his power from these dreams, and torments his victims in their sleep. Being the best candidate for Doctor Strange 2’s villain, there’s a lot of speculation that Nightmare could be connected in some way to WandaVision. After all, it’s widely believed that since the show and the movie are both using Scarlet Witch, WandaVision will lead into Doctor Strange 2. If that is indeed the plan, Nightmare could be the mastermind of a plot to make use of Wanda’s powers for his own gain. To properly save him for Doctor Strange 2, the series may only show a brief glimpse of him, and have his schemes carried out by an underling of some sort.

What’s actually going on in the show could be that Wanda’s reality warping powers are manifesting themselves in a chaotic way, and it’s possible that Nightmare is the one responsible for this. The comics have shown that Wanda tends to lose control of her powers when she’s under a severe amount of stress or in an emotionally unstable state of mind. Either of these problems could result from nightmares directly caused by the Doctor Strange villain.

Agatha Harkness

Of all the characters fans are talking about for WandaVision, perhaps the one with the strongest case for being the villain is Agatha Harkness, the elderly woman who taught Scarlet Witch magic when she was living at Avengers Mansion in the 1970s. Though not actually a villain, WandaVision could still reimagine her as one in the MCU. It’s long been rumored that Wanda and Vision’s nosy neighbor, a character played by Kathryn Hahn, is in fact Agatha Harkness. In the comics, Agatha is old enough to have lived through the Salem witch trials in the 17th century. Set photos of Hahn dressed up like a witch have reinforced the belief that Hahn is playing Wanda’s comic book mentor. Agatha may come to live next-door to Wanda because she’s aware of her potential with magic.

Ultron

Ultron Avengers Age of Ultron

Ultron could soon make a return to the MCU. The rumors about the classic Avengers adversary appearing in WandaVision are built on the idea that the villain from the comics has a reputation for coming back from anything. If he’s anything like the character in the source material, his death in Avengers: Age of Ultron shouldn’t rule out a resurrection, especially since Ultron is one of the team’s greatest and most menacing villains. Age of Ultron didn’t do him justice, so a second chance at making a good impression feels well-deserved. If Marvel were to use him again, their best opportunity is WandaVision. No (living) character in the MCU has a stronger connection to him than Scarlet Witch, who lost her brother to him. It’s possible that with her reality-warping abilities, Wanda can will someone back into existence. If that’s how Vision is brought back, Ultron could inadvertently be resurrected with him.

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