Legion has finally revealed its version of the iconic mutant Professor X - but how does he compare to his X-Men movie counterparts played by Patrick Stewart and James McAvoy? In Legion, Charles Xavier is the biological father of David Haller, the show's ultra-powerful mutant protagonist (or antagonist, depending on where we are in the story). For its first two seasons, Xavier was never directly evoked, but hinted at through some familiar imagery, like an empty wheelchair. But for Legion's final season, the man himself will be making an appearance. Games of Thrones and Doctor Who alum Harry Lloyd appeared as the famous mutant telepath - sporting a full head of hair - in the season's third episode, a flashback sequence telling the surprisingly sad story of how David's parents fell in love.

We obviously have only spent one episode with Lloyd's Xavier, but it's already easy to see there are some important differences between this version and the movie versions. The biggest difference is the most obvious - this version of Xavier is the father of David Haller. This is not something Legion just conjured up; David Haller was a crucial figure in the X-Men comics in the 90s, serving as a catalyst for the line-wide Age of Apocalypse event. It's a scenario rich with possibilities, and keeping Xavier off the board until the story's climax was an inspired choice for Legion. It's possible the film versions of Xavier could have fathered a child with Gabrielle Haller, but there was never any indication of that. This is an aspect of the character that the films never explored, which is not surprising. Legion is a dark, intimate story that wouldn't have worked in a two-hour blockbuster, squeezed in between scenes of Wolverine stabbing people and Dark Phoenix scowling.

Related: Legion Introduces Professor X (& Reveals David’s Problems Are His Fault)

This version of Xavier also exists in a different era than the movie versions. While the X-Men films have always played it fast and loose with its own continuity, Stewart and McAvoy are ostensibly portraying the same version of the character, who was seen in X-Men: First Class to be a man in his mid-20s by 1961. In Legion, Xavier fought in World War II at about the same age, two decades earlier than the film version. This Xavier was deeply affected by the horrors he endured during the war, which led him to a post-war psychiatric ward. Xavier didn't think much of the doctors, but used his time there to help others through their issues with his psychic abilities, including Gabrielle Haller. Charles and Gabrielle would fall in love, and Xavier altered the minds of the psych ward doctors to arrange their early release so they could start their lives together. Unfortunately, that little bit of hubris on Xavier's part my prove to be his damaged son's undoing.

Legion Professor Charles Xavier paints a patient

Despite the fact he's the benevolent face of mutantkind, Xavier has never been a morally pure character, which has always held true in the live action adaptations as well. Stewart's Professor X made some ethically questionable choices regarding Wolverine and Jean Grey, and McAvoy's Xavier was such a constant, selfish screwup that it was occasionally difficult to understand why anyone would follow the guy. This is definitely the case with Lloyd's Xavier, who makes quick, self-serving decisions without thinking through the possible consequences. It would seem that cost him his wife, and may end up costing David his life.

There's still a lot we don't know about Legion's version of Charles Xavier. There's been no hint that the X-Men exist, or that Xavier even started a school for mutants. Also, another surprisingly dark scenario is starting to seem more and more likely. In the comics, Xavier never knew about his son until he was an adult, but it's starting to seem highly improbable that Xavier didn't know this version of David. He raised him at least for a little while with Gabrielle before the Shadow King took hold, and we've still not seen the exact fallout from that. But most importantly, will we finally get to see David confront the man who abandoned him as an infant, damning him to years of psychic torture? It's the biggest question Legion has yet to resolve, and the answer is likely coming as the series hurtles toward its conclusion.

Next: Legion Reveals David's Plan (& It's More Green Lantern Than X-Men)