"Legion" has cast "Fargo" star Rachel Keller in an as-yet-unnamed lead role. Deadline describes Keller's role as "a scrappy, optimistic woman in her 20s," with powers potentially related to the human touch (much like Rogue).
"Legion," featuring Charles Xavier's son David Haller from Marvel Comics lore, is in development at cable network FX, with "Fargo" showrunner Noah Hawley on board as a producer. According to the official description, "Since he was a teenager, David has struggled with mental illness. Diagnosed as schizophrenic, David has been in and out of psychiatric hospitals for years. But after a strange encounter with a fellow patient, he’s confronted with the possibility that the voices he hears and the visions he sees might be real."
Keller is best known for her role as Simone Gerhardt on "Fargo," where she plays a femme fatale. She has also appeared in minor roles on "Supernatural" and "The Mentalist."
Both "Legion" and "Hellfire," a series based on longtime X-antagonists The Hellfire Club, are an extension of 20th Century Fox's X-Men film franchise, which started in 2000 with the original "X-Men" movie and continues through this year's "X-Men: Apocalypse" and beyond.