The new X-Men reboot has a new villain, and it’s a real treat for Marvel fans. According to industry insider Daniel Richtman, Mr. Sinister is now part of the X-Men reboot script.

Mister Sinister, also known as Nathaniel Essex, was a brilliant 19th-century scientist who became obsessed with human evolution and genetic perfection. His dangerous experiments eventually caught the attention of Apocalypse, one of the oldest and most powerful mutants. Apocalypse transformed Essex into Mr. Sinister, giving him incredible powers and a lifespan that stretched across centuries.
Before the X-Men appear in the new reboot movie, they will first show up in Avengers: Doomsday and Secret Wars. The cast for Doomsday has already been announced, and it includes half of the X-Men roster, featuring characters like Professor X, Cyclops, Beast, and many more. Doomsday has officially begun filming today in London, and the X-Men reboot is expected to release only after Secret Wars.
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.”
Avengers: Doomsday is set to release on May 1, 2026, followed by Avengers: Secret Wars on May 7, 2027.