"Legion," the X-Men universe pilot from FX, has cast "Fargo" breakout star Rachel Keller as its leading lady, according to Deadline. The project reunites her with "Fargo" creator Noah Hawley, who will write the pilot and serve as an executive producer on the new series.

Marvel TV and FX Productions will produce the pilot. Lauren Shuler Donner, Bryan Singer, Simon Kinberg, Jeph Loeb, Jim Chory, John Cameron and Steve Blackman will also serve as executive producers.

Keller will play a scrappy, optimistic woman in her 20s. Like most projects related to Marvel, details are limited, but speculation about her character ties her potential powers to fellow X-Men characters such as Rogue and Spyke, according to Deadline.

Keller's only credits before "Fargo" include the indie comedy "Hollidaysburg" and guest appearances on "The Mentalist" and "Supernatural."

"Legion" will follow the story of David Haller, based on the Marvel character Legion, the son of X-Men founder Charles Xavier. He has struggled with mental illness since he was a teenager and was diagnosed as a schizophrenic, spending years in and out of psychiatric hospitals. But after a strange encounter with a fellow patient, he confronted with the possibility that the voices he hears and the visions he sees might be real.

"'Legion' is just the sort of ambitious story that Noah excels at," Nick Grad, president of Orignal Programming, FX Networks & FX Productions, told Deadline in October. "His adaption of 'Fargo' for television was one of the most acclaimed television events in recent memory. It's also an honor to partner with Marvel on 'Legion' and to enlist such an accomplished team of Executive Producers to create this pilot."