The Marvel Cinematic Universe (MCU) is no stranger to surprises, but the latest revelations from Robert Downey Jr. and Benedict Cumberbatch have sent shockwaves through the fandom. At a press event in early August 2025, the two actors dropped tantalizing hints about their roles in the upcoming Avengers: Doomsday, set to hit theaters on May 1, 2026. Downey, previously known as the MCU’s Iron Man, will return as the iconic villain Victor von Doom, a.k.a. Doctor Doom, while Cumberbatch, the stalwart Doctor Strange, teased a rumored villainous turn for his character, Stephen Strange. These revelations, coupled with their new roles in the MCU’s Phase Six, have sparked intense speculation about the direction of Avengers: Doomsday and its sequel, Avengers: Secret Wars.

The announcement of Downey’s casting as Doctor Doom, made at San Diego Comic-Con in July 2024, was a seismic moment for the MCU. After a decade as Tony Stark, Downey’s shift to the Fantastic Four’s arch-nemesis marks a bold pivot. Co-director Joe Russo described Doom as a “three-dimensional” character, noting Downey’s unique ability to bring depth to the role through a self-crafted backstory and costume contributions. Cumberbatch, speaking at the Red Sea Film Festival in December 2024, expressed his initial shock, recalling how he texted Marvel Studios president Kevin Feige, “What the f—? Good what-the-f—,” upon hearing the news. The excitement stems not only from Downey’s return but also from the dynamic potential of Doctor Doom facing off against Earth’s Mightiest Heroes, including the Fantastic Four, Thunderbolts, and X-Men.

Cumberbatch’s comments about Doctor Strange’s role in Avengers: Doomsday have added fuel to the speculative fire. Initially, in January 2025, he told Variety that Strange would not appear in the film, citing a mismatch with the story following the pivot from the Kang-centric Avengers: The Kang Dynasty after Jonathan Majors’ departure. However, at Sundance later that month, Cumberbatch backtracked, coyly stating, “Don’t ever believe anything I say,” and confirming his involvement. Posts on X, including from @marvelousgeek__ and @BeyondReporter_, have since fueled rumors that Doctor Strange may not be the hero fans expect. Speculation suggests Strange could align with Doctor Doom as a villain, potentially influenced by his multiversal meddling in Doctor Strange in the Multiverse of Madness or his mission with Clea to address an incursion.

In Marvel Comics, Doctor Strange and Doctor Doom have a complex history, notably during the 2015 Secret Wars storyline, where Strange served as Doom’s right hand in a reality reshaped by the villain. The MCU’s Doomsday could draw from this, with Strange’s third eye and dark magic use hinting at a moral descent. Fans on X have theorized that Strange might become his universe’s Sorcerer Supreme only to be corrupted, setting up a clash with Downey’s Doom, who could seize mystical power to become a formidable threat. Cumberbatch teased at Tokyo Comic-Con that Strange’s arc involves grappling with the costs of his control-obsessed nature, suggesting a darker, more complex role.

The Avengers: Doomsday cast is a star-studded affair, with Chris Evans returning in an undisclosed role, alongside Anthony Mackie as Captain America, Tom Holland as Spider-Man, and Hayley Atwell as Peggy Carter. The Russo Brothers, directing both Doomsday and Secret Wars, aim to weave together the Avengers, Wakandans, Fantastic Four, and X-Men in a multiversal epic. Production began in April 2025 at Pinewood Studios in England, with location shooting in Bahrain. The film’s shift from Kang to Doom has streamlined the narrative, focusing on Doom’s debut as a multiversal menace, potentially tied to incursions—collisions of universes central to Secret Wars.

Cumberbatch’s confirmation of a third Doctor Strange film, likely releasing before Secret Wars in 2027, suggests his absence from Doomsday may be minimal, perhaps limited to a post-credits tease. Downey’s Doom, meanwhile, is poised to dominate, with theories suggesting he could dispatch a Doctor Strange variant to cement his power. The interplay between these two powerhouse actors promises a thrilling dynamic, whether as allies or adversaries. As Avengers: Doomsday shapes up to redefine the MCU, fans eagerly await how Downey and Cumberbatch will bring their iconic characters into this bold new chapter.