Surely, a lot of fans would like to see Marvel Studios and 20th Century Fox make a deal similar to Marvel's arrangement with Sony, sharing the X-Men and Fantastic Four the same way they do Spider-Man. As of now, there's no indication of that happening anytime soon, but on the television side, Marvel and Fox have agreed to collaborate on two non-MCU shows -- Hellfire and Legion. The first is set to air on regular, old, basic FOX, while Legion will land itself on their more adult cable channel, FX.
Legion follows David Haller, a troubled young man diagnosed with schizophrenia -- except multiple personalities aren't a symptom of mental illness, but rather his emerging mutant abilities. Lauren Shuler Donner, Bryan Singer, and Simon Kinberg of the X-Men films are exec-producing along with Marvel TV head Jeph Loeb, Jim Chory and John Cameron. Writing the pilot episode is Noah Hawley, the creator and primary writer of FX's Fargo.
There's little we know beyond those details, but it's clear from Hawley's involvement they're looking for familiar talent -- especially those who've already worked for FX. Which means it's really no surprise to learn (via Deadline) that Legion has cast Fargo's Rachel Keller as its female lead: a scrappy, optimistic woman in her 20s.
Her role as Simone Gerhardt on Fargo was the first high-profile acting gig for Keller, but she quickly became a real fan favorite. Obviously, Hawley seems happy to continue working with her and FX doesn't want to lose her. All in all, the casting appears to be a good decision and only adds to the growing pedigree of those involved with the Legion pilot.
Whether Keller's character is a mutant is unclear, but there's every chance she plays the hospital patient who first convinces Haller he isn't just schizophrenic but gifted. Then again, she may be someone who meets Haller once he's no longer institutionalized, and if that's the case, it's hard to know which Haller she first meets.
And if that sounds confusing, it's because it is. At least a little. Haller, better known as Legion in the pages of Marvel Comics, does suffer from dissociative identity disorder and each of his personalities control one of his many mutant powers (telepathy, pyrokinesis, super strength, etc.). The obvious erratic nature of his powers makes Legion more of an anti-hero than true superhero, making Haller's story a good fit for FX's more mature content. Oh! And he's Charles Xavier's long lost son, but I wouldn't be surprised if Legion chose to ignore that bit for simplicity's sake.
Dates have not yet been set for FX’s Legion or FOX’s Hellfire (working title) pilots.