Avengers: Doomsday: All About Robert Downey Jr.'s Return and What Was Revealed at Comic-Con

Marvel has big things in store for Avengers: Doomsday.

Originally titled Avengers: The Kang Dynasty, the upcoming fifth Avengers film has undergone many changes since it was first announced at San Diego Comic-Con in July 2022. 

Following the introduction of He Who Remains on Disney+'s Loki, the Avengers project was initially going to revolve around an alternate-timeline variant of the character Kang the Conqueror, played by Jonathan Majors. However, after Majors was found guilty of assault and harassment in his misdemeanor trial in December 2023, Marvel reworked the script.

Many new details about the film were announced at San Diego Comic-Con in July 2024, including the updated title and the new villain. In a standout moment during the Marvel presentation, it was announced that Robert Downey Jr., who famously played superhero Iron Man, would return to the MCU as Doctor Doom. 

From the cast to the release date, here’s everything to know about Avengers: Doomsday. 

Who is the villain of Avengers: Doomsday?

While the Infinity Saga revolved around Thanos (Josh Brolin) as the main villain, the Multiverse Saga will debut Doctor Doom as the big bad in Avengers: Doomsday. Fittingly, the role will be played by Robert Downey Jr., who previously starred as Avengers superhero Iron Man who sacrificed himself to save the world in Avengers: Endgame.

The announcement was made during San Diego Comic-Con in July 2024, as Downey Jr. emerged onto the panel's stage among a group of actors wearing masks and robes. “New mask, same task," Downey said as he took off Doctor Doom’s notable silver mask. "What did I tell ya? I like playing complicated characters."

So, how exactly can Downey Jr. play both Iron Man and Doctor Doom? As previous films in the Multiverse Saga have teased, the MCU is teeing up for a big collision of parallel universes in Avengers 5 and 6. This has led many fans to believe that Downey Jr. will be playing an alternate-universe version of Stark, where he became the villainous Doctor Doom instead of the heroic Iron Man.

Who is in the Avengers: Doomsday cast?

In addition to Downey Jr. as the chief villain, it was confirmed during Comic-Con that both the Fantastic Four and the Thunderbolts would appear in Avengers 5 and 6. 

For Fantastic Four, that includes Pedro Pascal as Reed Richards/Mr. Fantastic, Vanessa Kirby as Sue Storm/The Invisible Woman, Joseph Quinn as Johnny Storm/The Human Torch and Ebon Moss-Bachrach as Ben Grimm/The Thing. 

From the Thunderbolts, the following actors are expected to appear: Sebastian Stan as Bucky Barnes, Florence Pugh as Yelena Belova, David Harbour as Red Guardian, Wyatt Russell as U.S. Agent, Olga Kurylenko as Taskmaster, Hannah John-Kamen as Ghost and Julia Louis-Dreyfus as Valentina Allegra de Fontaine.

What is Avengers: Doomsday about?

An official plotline for the movie hasn’t been announced yet, though the comics could tease what’s in store. In 2011, a multi-issue comic was released titled Ultimate Comics: Doomsday, in which the Fantastic Four teamed up with various Marvel superheroes in hopes of stopping a mysterious villain trying to destroy their timeline. 

In the comics, they eventually discover that the mysterious villain is a familiar, heroic face who turned bad in the multiverse, perfectly setting things up for Downey Jr.’s return. 

Who is directing Avengers: Doomsday?

Anthony and Joe Russo are slated to helm the project after a few previous director switch-ups. The movie will mark their big return to the MCU after previously directing Captain America: The Winter Soldier (2014), Captain America: Civil War (2016), Avengers: Infinity War (2018), and Avengers: Endgame (2019). 

Who is writing Avengers: Doomsday? 

Not only are the Russo brothers slated to return to the MCU, but Stephen McFeely, who co-wrote all four of the Russos’ Marvel films, will pen the script, per Variety. 

When will Avengers: Doomsday be released?

The movie is slated to hit theaters in May 2026 as part of the MCU’s Phase 6. 

Will there be another Avengers movie? 

Avengers: Doomsday isn’t the only Avengers project in the works. It will be followed by Avengers: Secret Wars, which is slated to release a year later in May 2027. 

Many of the same production team will be involved including the Russo brothers as directors and Stephen McFeely as the screenwriter. The cast will also include Downey Jr. as Doctor Doom and the stars of The Fantastic Four and Thunderbolts*.