The X-Men franchise surprised fans with news that the Marvel-ous mutants would spawn not one, but two TV series, the more developed of which will see Fargo showrunner Noah Hawley taking on Charles Xavier’s son Legion. Now, our first official star has arrived, tapping Fargo Season 2 face Rachel Keller for a potentially rogue role.

Per The Hollywood Reporter, Keller becomes the first official cast member of the new X-series, as well as its female lead, described as “a scrappy and optimistic woman in her 20s.” Additional details are being kept under wraps, but THR speculates the character might prove an incarnation of Rogue (previously played in the films by Anna Paquin), or Spyke.

Legion follows the story of David Haller, a young mutant struggling with schizophrenia and psychiatric incarceration, who soon learns from a fellow patient that his voices and visions may in fact be real. Created for the New Mutants in 1985, the character is also noted as the son of Professor Charles Xavier and Gabrielle Haller.

Fargo showrunner Hawley will write the pilot and serve as an executive producer alongside Lauren Shuler Donner, Bryan Singer, Simon Kinberg and Marvel’s Jeph Loeb. Previously, Hawley also deemed it unlikely that Legion would maintain much, if any connective tissue with the films.

Last reports suggested Legion likely to begin shooting in January, but what do we make of the first addition?

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