The Final Season Of 'Legion' Casts 'Game Of Thrones' Star Harry Lloyd As Professor X

For two seasons, the FX series Legion has focused on David Haller (Dan Stevens), a man who believed he was schizophrenic but discovered he might be the most powerful mutant in the world. In the comics, that's mostly because he's the son of Professor Charles Xavier, something that has only been hinted at on the show. We haven't seen the telepathic mutant appear on the X-Men series yet, but that will change with the show's third and final season.

Legion has landed Harry Lloyd as Professor X, though the extent of the character's involvement in the end of the series has yet to be revealed. Lloyd may best be known for his role on Game of Thrones as Viserys Targaryen, the corrupt, doomed brother of Emilia Clarke's Daenerys Targaryen.

News of Professor X on Legion was announced at FX's Television Critics Association panel for the series by executive producer Noah Hawley. The announcement also included the addition of Stephanie Corneliussen (Mr. Robot) as David Haller's mother Gabrielle.

Funnily enough, Harry Lloyd is younger than Dan Stevens. That means there's a chance we'll only see Professor X appearing in flashbacks on Legion instead of in the actual present day timeline. After all, we recently learned that the third season of Legion will involve time travel, thanks to the introduction of Lauren Tsai as a character named Switch.

In a tease from the third season shown during the TCA panel, David brought Switch into his mindspace with the intention of using her time travel powers. It wouldn't be surprising if attempting time travel results in some unexpected consequences, perhaps taking David back to his past to learn more about his parents, especially when it comes to Xavier's struggle with his son's uncontrollable powers. Executive producer Hawley explained (via The Wrap):

"We know enough, even in the mythology of the show, to know that when David was born his father went off to fight [Amal Farouk] and kick Farouk out of his body. And so I think what we're going to explore, is that story."

The good news is that Legion wasn't forced to fit in with any of the rest of the confusing X-Men timeline. Hawley still had to talk to the higher-ups at Fox about using Professor X, but they didn't give him any restrictions at all:

"The movie studio definitely controls that story and those characters and there was a negotiation that had to go on. Going into this third story, that conversation began to be had at the highest levels, because I can't finish the story unless I can do it. The good thing with 'Legion' is that our reality is so detached from the comics — or anything — because it's David's subjective experience. The tesseracts in his reality doesn't really have to linearly tie to anything we've seen before."

So even though we'll be seeing Professor X in Legion this season, it will all be through the perspective of David. As has become customary with Legion, the story that unfolds is bound to be a total mindfuck. So that could mean the Professor X we meet won't be based in a normal reality at all.

The third season of Legion debuts on FX sometime in June.