Who Is Nathaniel Milbury? Adam Driver’s Mysterious ‘X-Men’ Character, Explained

Forget Magneto, 'X-Men' Finally Reveals Adam Driver Is Playing Its Greatest Villain

Published Aug 17, 2026, 8:29 AM EDT

Hannah has been writing about horror, sci-fi, and all things nerdy since 2021. At Collider, she covers news and conducts interviews, along with contributing features that dive deep into genre storytelling and why it works. If there’s something lurking in the shadows, she’s probably already writing about it if she's not too busy watching a tape from her VHS collection.

Marvel Studios has finally started putting names and faces to its new generation of X-Men, and some of those names need considerably less explanation than others. Sadie Sink is Jean Grey, Kit Connor is Cyclops, Christopher Abbott is Charles Xavier, Maya Boyd is Storm, Samara Weaving is Emma Frost, and Inde Navarrette is Rogue. Then there is Adam Driver. Driver was one of the biggest surprises to come out of Marvel's D23 presentation, particularly after years of speculation about when the Star Wars actor might finally make his way into the Marvel Cinematic Universe.

His casting also immediately raised questions because Marvel did not introduce him with the instantly recognizable supervillain name fans might have expected. Instead, Driver revealed that he is playing Nathaniel Milbury. If that name does not immediately ring a bell, that is probably intentional. Nathaniel Milbury is hardly one of the most famous names in X-Men history, but it has a very important connection to one of the team's greatest enemies. Marvel may be playing coy about exactly what Driver's role in X-Men will look like, but Nathaniel Milbury has a very, very Sinister history.

Nathaniel Milbury Is One of Mister Sinister's Many Names

Image via Marvel Entertainment

Nathaniel Milbury is an alias associated with Nathaniel Essex, better known to X-Men fans as Mister Sinister. Marvel's own character history lists variations including Nathan Milbury and Mike Milbury among the many identities Essex has used over the years. That makes Marvel's decision to introduce Driver as Milbury instead of simply announcing him as Mister Sinister especially interesting. Mister Sinister is one of the X-Men's longest-running and most dangerous villains. Created by Chris Claremont and Marc Silvestri, the character made his full debut in 1987's Uncanny X-Men #221, although his influence on the X-Men's lives stretches much further back within Marvel continuity.

Born Nathaniel Essex in Victorian England, he was a scientist obsessed with evolution and genetics whose work eventually brought him into contact with Apocalypse. Essex's experiments and transformation ultimately turned him into the virtually immortal geneticist the X-Men would come to know as Mister Sinister. That obsession with genetics is what makes Sinister particularly dangerous to the X-Men. He does not simply want mutants dead. He wants to understand, manipulate, clone, and ultimately control them. His experiments have made him a recurring nightmare for mutantkind, but Scott Summers and Jean Grey have been at the center of his plans for decades.

Sinister has a particular fascination with the Summers and Grey bloodlines, believing their genetics could produce an extraordinarily powerful mutant. His interference in their lives eventually led to one of the strangest chapters in X-Men history: Madelyne Pryor. Madelyne was created by Sinister as a clone of Jean Grey, and she later married Scott and gave birth to Nathan Summers, the mutant who would eventually become Cable. Marvel's own history of the villain identifies Madelyne as one of Sinister's creations and specifically highlights his experiments on Cyclops, Havok, and their bloodline. That history makes Driver's casting particularly notable considering Jean Grey and Cyclops are already confirmed as central members of Marvel's new X-Men lineup. If Nathaniel Milbury eventually reveals himself as the MCU's Mister Sinister, Marvel already has two of the characters most closely connected to his comic-book obsession positioned right alongside him.

Is Adam Driver Actually Playing Mister Sinister?

Image via Marvel Comics

All signs certainly point in that direction, but Marvel's wording is worth paying attention to. Driver specifically announced his character as Nathaniel Milbury, not Nathaniel Essex and not Mister Sinister. While the Milbury name has an established connection to Essex in the comics, that does not necessarily tell us exactly how Marvel Studios plans to adapt the character. The MCU has plenty of experience remixing comic-book identities, origins, and relationships, and X-Men gives Marvel an enormous mythology to reshape. Nathaniel Milbury could simply be an identity Essex is using before his true nature is exposed, allowing Driver's character to initially operate without the X-Men realizing who they are dealing with. Marvel could also be borrowing the Milbury name while making larger changes to Sinister's history.

What we do know is that Marvel did not pick the name Nathaniel Milbury out of nowhere. It is deeply connected to Mister Sinister, a villain whose comic history already intersects directly with several members of the MCU's new X-Men. Even Marvel's official character profile treats Milbury as part of Essex's sprawling collection of identities. For now, Marvel appears perfectly happy to let audiences wonder exactly why Driver is Nathaniel Milbury instead of Mister Sinister. Considering the character he is connected to, though, being suspicious is probably a very good idea.

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  Jean Grey

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  Inde Navarrette

  Rogue / Anna Marie

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  Kit Connor

  Scott Summers / Cyclops

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  Samara Weaving

  Emma Frost