While Avengers: Doomsday is stacked with several heroes and villains, a supposed leak suggests another Marvel icon will return as well. This "leak" features promotional images for the movie depicting Doctor Doom's Latverian Witches, as well as another masked character who could be one of Earth's Mightiest Heroes.
According to ComicBookMovie.com, the latter character is said to be named “Boris.” Though this sounds like a silly name for a villain, it could be a codename for a much bigger character. Though it hasn't been confirmed whether these promotional shots are legitimate, they hint at Boris being none other than Doctor Strange.

Avengers: Doomsday hints at Doctor Strange being a villain
Despite being a major figure in the Multiverse Saga, Doctor Strange has been noticeably absent from Doomsday’s cast. It seems unlikely that such a powerful hero would ignore such a massive threat to the multiverse. However, it seems like Marvel is hiding a major spoiler about Strange, specifically him working with Doctor Doom as "Boris."
The sorcerer was last seen in Doctor Strange in the Multiverse of Madness, leaving with Clea to stop an Incursion that he caused earlier in the film. The eye-like symbol on Boris' forehead reflects the third eye that Strange developed at the end of the film. Back in March, industry scooper Daniel Richtman shared a rumor that Doom's right-hand man would be a wizard who uses a sling ring and wears a mask with a "slot for a third eye on his forehead." Sound familiar?
This reported leak not only implies that Doctor Strange is an ally of Doom's but also that Clea is one of the Latverian witches, quite possibly the one dressed in purple. Since Strange and Clea last teamed to stop an Incursion, they may be working with Doctor Doom to try to “save” the Multiverse from destruction.

Doctor Strange may play a role based on the comics
Doctor Strange siding with a villain like Doom may surprise some audiences. However, it actually aligns with his actions in the comics. In the "Secret Wars" storyline, Strange teams up with Doom to try to stop a series of incursions from destroying the Multiverse. This culminated in Doom creating Battleworld, becoming its "God Emperor," and making Strange his right-hand man.
Since Doomsday is setting up an adaptation of this storyline with Avengers: Secret Wars, it makes sense that the filmmakers would give Strange a similar role as one of Doom’s allies. The movie's trailers hint at the heroes' morals being tested in the face of total annihilation, so Strange may have already crossed over to the "dark" side to stop this overwhelming threat.
Fans have already seen Strange use dark forces to do what he thought was right. In his last film, he used the mystical Darkhold to dreamwalk into his variant's corpse to save America Chavez, despite the risk it posed to the multiverse. Since his actions caused an incursion, joining forces with Doom could be his way of trying to make up for his mistakes. Only time will tell where Strange's allegiance lies.
Avengers: Doomsday arrives in theaters on December 18, 2026.
