Alan Cumming and Rebecca Romijn celebrate joining cast of Avengers: Doomsday

Alan Cumming and Rebecca Romijn have celebrated the fact that they're reprising their X-Men roles in Avengers: Doomsday.

Marvel executives announced the massive cast line-up for the next Avengers film during a five-and-an-half-hour livestream on Wednesday, confirming the return of Marvel mainstays such as Chris Hemsworth, Sebastian Stan, Tom Hiddleston and Paul Rudd.

The most surprising names on the list were Cumming, Romijn and their X-Men co-stars Patrick Stewart, Ian McKellen, Kelsey Grammer and James Marsden, as this revealed that the original X-Men crew had been invited into the Marvel fold.

Cumming, who is reprising his role as Kurt Wagner/Nightcrawler 22 years after starring in 2003's X2, celebrated the news on Instagram by posting a video in which he jumped up and down steps and prowled around like Nightcrawler inside a house.

He simply captioned the post, "Never say never!"

Romijn, who played the blue-skinned mutant Mystique in the original trilogy, shared a throwback photo of herself in character as well as her name on the back of a director's chair. She added, "She's back. True. Blue."

The original X-Men trilogy ran between 2000 and 2006. In those films, Stewart portrayed Professor X, McKellen was the villain Magneto, Grammer played Hank McCoy/Beast and Marsden portrayed Scott Summers/Cyclops. Stewart and McKellen have reprised their roles more times since, while Grammer most recently made a cameo as Beast in 2023's The Marvels.

Some of their notable co-stars were missing from the announcement, such as Hugh Jackman, Halle Berry, Famke Janssen and Anna Paquin. It remains to be seen if they will make a surprise appearance in the film.

Before the livestream, it was already known that Robert Downey Jr., Anthony Mackie, Pedro Pascal, Vanessa Kirby, Joseph Quinn and Ebon Moss-Bachrach would star in Avengers: Doomsday.

The new cast additions also included Black Panther stars Letitia Wright, Winston Duke and Tenoch Huerta Mejia; Shang-Chi's Simu Liu; Deadpool & Wolverine's Channing Tatum; and Thunderbolts actors Florence Pugh, Wyatt Russell and David Harbour.

Avengers: Doomsday is now in production ahead of a release in May 2026.