Adam Driver has explained his decision to join the "X-Men" reboot as Mister Sinister, a role he accepted after turning down many Marvel movies over the years. During a recent appearance on "Jimmy Kimmel Live!", Driver stated that while he was a fan of other Marvel projects, this specific film felt like the right time.

Driver attributed his decision to the project's creative team and script. He noted that it was "really 'X-Men,' Jake Schreier, who’s the director, his idea for it, and that it’s Kevin Feige. It all kind of came together. The script is really cool."

The actor admitted to being highly selective about joining the MCU due to the massive scale of the audience. Driver told the host that "a lot of people are going to watch it, and if it’s bad, you know, a lot of people will see you being bad. Plus, I don’t want to mess it up."

Marvel head Kevin Feige shared his perspective on the casting process during the "Happy Sad Confused" podcast. Feige said it has become a "tradition" to meet with Driver on Zoom to discuss roles, which Driver then turns down. Feige stated, "It’s no secret we’d like to [work with Adam]. But it’s a tradition to Zoom with him and then he passes. That’s a long-lived tradition. He couldn’t be more cordial. He is usually upfront about how he is feeling."

In the upcoming film, Driver will portray Dr. Nathaniel Essex, also known as Mister Sinister, described as a superintelligent, shape-shifting telepath. He will serve as the main antagonist facing off against a cast that includes Sadie Sink as Jean Grey, Inde Navarrette as Rogue, Kit Connor as Cyclops, Christopher Abbott as Charles Xavier, Maya Boyd as Storm, and Asa Germann as Angel.