A new update on the X-Men reboot film has been revealed. It is rumored that a major supervillain from the X-Men comics, known as Mr. Sinister (Nathaniel Essex), is now part of the X-Men reboot script.
According to industry insider Daniel Richtman, his Patreon post revealed that the current draft of the X-Men film reportedly features Mr. Sinister as the main villain. Filming is expected to begin after Avengers: Secret Wars.
Who is Mr. Sinister in Marvel Comics?

In Marvel Comics, Mr. Sinister, also known as Nathaniel Essex, was a scientist from the 19th century who was obsessed with evolution, genetics, and making humans perfect. He was turned into Mr. Sinister by an ancient mutant named Apocalypse, who gave him powers and made him live much longer. He’s incredibly powerful — he has abilities like telepathy, telekinesis, shapeshifting, superhuman strength, rapid healing, and advanced scientific knowledge. He’s also practically immortal.
I heard that the Russo Brothers have reportedly signed a new deal with Marvel Studios to oversee additional projects for the next saga. This also includes the X-Men reboot movie.

During the Disney APAC Content Showcase, Marvel President Kevin Feige spoke about the future of the X-Men, calling their return to Marvel Studios “a dream come true.”
Feige said, “I think you will see that continue in our next few movies with some X-Men players that you might recognize.” He added, “Right after that, the whole story of Secret Wars really leads us into a new age of mutants and of the X-Men. Again, [it’s] one of those dreams come true. We finally have the X-Men back.”
Meanwhile, Marvel has officially announced that several popular X-Men actors will return in Avengers: Doomsday, including Ian McKellen (Magneto), Kelsey Grammer (Beast), James Marsden (Cyclops), Channing Tatum (Gambit), Rebecca Romijn (Mystique), Patrick Stewart (Professor X), and Alan Cumming (Nightcrawler).
Filming for Avengers: Doomsday has begun in the United Kingdom. Some of the scenes are being filmed at the X-Mansion, where the X-Men will wear comic-accurate suits.
Avengers: Doomsday is set to be released on May 1, 2026, and Avengers: Secret Wars will be released on May 7, 2027.
Source: Daniel Richtman