The trailer for ‘Avengers: Doomsday’ teases the return of new and old MCU stars — here’s everything we know

Initially, Kang was set to be the next major villain for the Avengers, but Kang actor Jonathan Majors was fired by Marvel in 2023 after he was convicted of one misdemeanor count of reckless assault and one count of harassment related to an assault of his ex-girlfriend. (Majors, who pleaded not guilty, was sentenced in 2024 to a 52-week domestic-violence program.)

A month before Majors was fired, the “Loki” season two finale seemingly diminished Kang’s role in the multiverse when Tom Hiddleston’s titular antihero rewrote the timeline, providing an easy route to eliminate Kang from the MCU.

Then, in July 2024, Marvel announced at the San Diego Comic-Con that Robert Downey Jr., known for playing the beloved hero Iron Man for over a decade, had been cast as the Marvel Comics villain Doctor Doom.

While there had been speculation that Downey Jr. might return to the MCU at some point, the announcement came as a shock to many fans. The actor only left the franchise a few years prior, when (spoiler alert!) Iron Man sacrificed his life at the end of “Endgame” to save the universe.

The answer to how this recast is possible lies in the multiverse — the various dimensions that are interconnected through time and space.

Recent Marvel projects have introduced fans to alternate versions of heroes from other universes, including Doctor Strange, Scarlet Witch, Deadpool, Wolverine, and more. It seems likely that Downey Jr.’s version of Doom is from a different universe than Downey Jr.’s version of Iron Man.

Doom is the Fantastic Four’s main enemy in the comics. In fact, he appeared in the 2005 “Fantastic Four” movie, played by Julian McMahon — back when Chris Evans played the Human Torch, not Captain America.

Marvel Studios’ head honcho, Kevin Feige, already confirmed that the foursome’s latest reboot, “The Fantastic Four: First Steps,” takes place in a different universe than the main “Avengers” series. Perhaps in this universe — where Joseph Quinn plays the Human Torch — Tony Stark took the path toward villainy rather than heroism.

There have also been versions of Iron Man in the comics that have turned into Doom. Most notably, a young Victor Von Doom body-swapped with Stark as a young man in 2010’s “What If? Iron Man: Demon in an Armor #1.”

Doom himself took up the Iron Man mantle in “The Infamous Iron Man” series in 2016. So, there is some precedent for blending their identities.

If the villain does come from another universe, Marvel Studios could still cast another version of Doom for the main MCU on Earth-616 if they wanted someone else to take over the role in the future.

The internet was divided about Downey Jr.’s return, with many criticizing Marvel Studios for playing the nostalgia card and being too safe with their casting choice.

Some fans also said this move would ruin Downey Jr.’s final performance in “Endgame” and the legacy of Doctor Doom, one of Marvel’s most popular comic-book villains.

But Rob Mitchell, the director of theatrical insights at Gower Street Analytics, told Business Insider in July 2024 that bringing him and the Russo brothers back is a logical decision.

“The chances are people are going to go, ‘This is interesting. What are they doing? I’ve got to see this. Even if I just want to be able to have an opinion on why.’ I get it from a business perspective, I can’t really see the downside,” he said.

“Fans would’ve expected big things from an ‘Avengers’ movie anyway,” he added.

Mitchell said that people’s curiosity about Downey’s role in “Doomsday” will draw them in, especially to see if the actor changes his appearance.

“Will he look like Tony Stark, or will they do something to make him look different? It’s Hollywood, there’s plenty of makeup. There’s lots of Ryan Reynolds in ‘Deadpool & Wolverine,’ but they don’t all look the same.”

Downey Jr.’s casting comes amid conversations about whether audiences are tired of the superhero genre. While it’s not a new concern, Mitchell said that MCU fatigue hasn’t deterred fans.

“Can we really have a conversation about MCU fatigue when ‘Deadpool’ just made $430 million in four days? This is a film that we are anticipating being only the second R-rated film to do a billion dollars. And clearly, that’s where it’s heading. So you can talk MCU fatigue after that,” he said.

“Loki” creator Michael Waldron cowrote the script for “Doomsday” alongside Stephen McFeely, who cowrote MCU movies including “Endgame,” “Infinity War,” “Captain America: Civil War,” and “Captain America: The Winter Soldier.”

It’s safe to assume that the events of “Loki” will factor into the plot of “Doomsday,” since Loki is now the one holding the multiverse together with his bare hands.

“Loki,” “What If,” “Doctor Strange in the Multiverse of Madness,” and “Ant-Man and the Wasp: Quantumania” all warned that multiversal interactions could lead to a war between universes or the universes colliding into each other.

Though Kang is no longer Marvel’s big-picture villain, a collision between different worlds still seems to be the Avengers-level threat that will be faced in the forthcoming films.

Marvel Studios seems to be adapting two major events from its mid-2010s comics, “Time Runs Out” and “Secret Wars.” In this run of comics, both written by Jonathan Hickman, the multiverse is dying because an alien race called the Beyonders has created living bombs to wipe out everything.

Attempts to kill living bombs lead to multiple earths from these universes colliding, wiping out both universes. The Beyonders’ plan succeeds, but Doctor Doom, Doctor Strange, and Molecule Man kill the alien race, steal their power, and create a new world with Doom as the world’s god.

Other heroes also survive the decimation using special life raft machines. When they escape, they defeat Doom and restore the universe.

Incursions have already been alluded to in “Doctor Strange in the Multiverse of Madness.” While they have the same effect as the comic book, the cause is prolonged multiversal traveling.

It is likely that something before or during “Doomsday” kicks off that incursion in the main MCU universe, leading to a violent battle between multiple worlds.

Since “Endgame,” many of the main heroes from the MCU’s Infinity Saga have retired or died, and new characters have been introduced through various films and Disney+ shows.

In March 2025, when Marvel confirmed that “Doomsday” was in production, the studio announced a slew of cast members via an hourslong livestream.

In addition to Downey Jr., several other MCU stalwarts will be back, including Chris Hemsworth as Thor, Tom Hiddleston as Loki, Paul Rudd as Ant-Man, and Simu Liu as Shang-Chi.

Anthony Mackie and Danny Ramirez, who most recently reprised their Marvel roles in “Captain America: Brave New World,” will also return in “Doomsday” as Captain America and Falcon.

Additionally, the movie will include actors who’ve starred in Marvel’s newer films, “Thunderbolts*” and “The Fantastic Four: First Steps.”

The critical favorite “Thunderbolts*” centers on a ragtag group of assassins and spies who’ve already appeared in previous MCU projects and must work together on a mission.

Cast members include Sebastian Stan as Winter Soldier, Wyatt Russell as John Walker, Florence Pugh as Yelena Belova, David Harbour as Red Guardian, Hannah John-Kamen as Ghost, and Lewis Pullman as Sentry. This team will return in “Doomsday.”

After making their MCU debuts in “The Fantastic Four: First Steps,” Pedro Pascal, Vanessa Kirby, Joseph Quinn, and Ebon Moss-Bachrach will reprise their roles in “Doomsday” as Mr. Fantastic, Invisible Woman, Human Torch, and The Thing, respectively.

“Doomsday” will feature the returns of “Black Panther: Wakanda Forever” stars Letitia Wright, Tenoch Huerta Mejía, and Winston Duke as Shuri, Namor, and M’Baku, respectively.

Getting dizzy? Well, buckle up. After Disney’s $71 billion deal to buy 21st Century Fox’s entertainment assets, everyone from the “X-Men” franchise is fair game as well.

Kelsey Grammer is confirmed to appear in “Doomsday,” likely reprising his role as Beast after his appearance in the end-credits scene of “The Marvels.”

He’s not the only “X-Men” alum who will be part of “Doomsday.” The cast list includes Patrick Stewart (Professor X), Ian McKellen (Magneto), Alan Cumming (Nightcrawler), Rebecca Romijn (Mystique), and James Marsden (Cyclops).

Fans of Channing Tatum’s performance as Gambit in “Deadpool & Wolverine” will also rejoice in the news that he’ll appear in “Doomsday.”

The list of confirmed cast members noticeably excludes major MCU stars like Mark Ruffalo (Hulk), Jeremy Renner (Hawkeye), Benedict Cumberbatch (Doctor Strange), Tom Holland (Spider-Man), Brie Larson (Captain Marvel), and Elizabeth Olsen (Scarlet Witch). But that doesn’t mean more casting announcements or surprise cameos are out of the question.

Chris Evans, famous for playing Steve Rogers aka Captain America, unofficially retired from Marvel after wrapping “Endgame.”

Remember: After the Avengers pull off the “time heist” to prevent Thanos from collecting the Infinity Stones, Steve goes back in time to return the Stones to their original points of collection. With his time-traveling power, Steve decides to stay in the past and grow old with his true love, Peggy Carter, played by Hayley Atwell. He then passes on the Captain America mantle to his friend Sam Wilson, formerly Falcon, played by Anthony Mackie.

Evans was not included in the initial casting announcement for “Doomsday,” but he was confirmed to appear in the movie when a teaser was released in December 2025.

The teaser includes a clip of the character holding a baby, apparently living a quiet life as a father. It ends with the title screen, “Steve Rogers Will Return In Avengers: Doomsday.”

Evans also appears in the first official trailer. This clip shows him greeting Thor, then summoning Thor’s hammer Mjölnir, which can only be wielded by those it deems worthy. So far, we’ve seen multiple characters manage it: Thor, Thor’s father Odin (Anthony Hopkins), Thor’s sister Hela (Cate Blanchett), Vision (Paul Bettany), Jane Foster (Natalie Portman), and, yes, Steve Rogers.

Evans could be returning to the action as the hero we know and love — anything is possible with the advent of time travel, right? — or a version of Steve from a different dimension.

However, some fans have theorized that Evans is playing a multiversal version of Thor. Or maybe it’s just Loki in disguise as Steve — one of the MCU’s favorite bits.

Evans could even be returning as a multiversal version of Johnny Storm, aka the Human Torch, just as he did in a cameo for “Deadpool & Wolverine.” Could Evans play both Steve and Johnny in the same movie? Could we have two different Human Torch variants meeting face-to-face? Could one of those variants be worthy enough to wield Mjölnir? Crazier things have happened.

“Thunderbolts*” includes two post-credits scenes, but the second one is far more significant. (Spoilers ahead!)

The scene is set 14 months later, showing the Thunderbolts, who have now been rebranded to the New Avengers, in the Watchtower. They’re all wearing slightly different wardrobes and have undergone other small changes in their appearances since the last scene in the movie.

As the team is discussing Sam Wilson filing for a copyright for the Avengers, they’re interrupted by the Fantastic Four spacecraft entering orbit.

If that scene feels separate from the tone of “Thunderbolts*,” it’s because it was filmed on an entirely different movie set.

In spoiler interviews with various outlets published after the release of “Thunderbolts*,” director Jake Schreier said that the scene is from “Doomsday” and was recently filmed on the set of the ensemble film.

Schreier told Variety that he got to see the drafts and contribute to make sure it felt like an accurate and honest depiction of the characters. He was also present when the scene was filmed, but the Russo brothers directed it.

“I was very happy to be there and lucky to be there,” Schreier told Entertainment Weekly. “It was so fun to see your characters go off into this bigger context. We’ve been living in our own contained world, but it was really fun to see them there.”

“The Fantastic Four: First Steps” introduces Franklin, the newborn son of Reed Richards and Sue Storm, aka Mr. Fantastic and Invisible Woman.

Franklin is super-powered, though it’s unclear exactly what his powers are. The planet-destroying villain Galactus tries to bargain with the Fantastic Four, offering to spare Earth if they let him keep the baby, but they refuse.

After the heroes defeat Galactus, the movie’s mid-credits scene jumps to four years later, when Franklin is a toddler.

A mysterious man in a green cloak approaches Franklin. The boy is touching the man’s face, but the stranger’s identity is concealed by his hood.

It seems clear that this man is Doctor Doom. The screen then cuts to black, and text appears: “‘The Fantastic Four’ will return in ‘Avengers: Doomsday.'”

Whatever Doctor Doom’s evil plan may be, it looks like Franklin will play an important role.

Much like the one-two punch of 2018’s “Infinity War” and 2019’s “Endgame,” Marvel Studios is already preparing a sequel to “Doomsday.”

The Russo brothers-directed follow-up, “Avengers: Secret Wars,” is set for release one year later on December 17, 2027.