‘LEGION’ HEIR

‘X-Men’ character gets his TV closeup in new FX series

I F Dan Stevens was looking to get as far removed as possible from the aristocratic world of “Downton

Abbey,” he’s certainly found it with “Legion.” In Marvel’s newest TV drama, premiering 10 p.m. Wednesday on FX, the English actor, best known as “Downton” heartthrob Matthew Crawley, has ditched the starched shirts and tails for a more disheveled look as David Haller, the powerful mutant at the center of this “X-Men”-inspired story. Diagnosed in childhood as a schizophrenic, the 30-something David we meet in the “Legion” pilot is complacently living in a psychiatric hospital — until a startling encounter makes him realize the voices and visions he experiences might be real.

“I, funnily enough, have a friend from college who was an absolute ‘Legion’ nut and spent most of the ’90s collecting [the comic books],” Stevens, 34, told reporters recently. “He just had a conniption when he heard I was doing this and [he] is an amazing resource … I can tap into it and say, ‘Tell me what I need to know.’ Because we kept it fairly obscure, particularly in the pilot. There are details, visual elements that you might recognize from the comics, but we’re not directly adapting anything from the comic book story.”

Not only does “Legion” divert from the Marvel Comics by Chris Claremont and Bill Sienkiewicz, but it looks nothing like any superhero series to date. That’s largely because it’s the brainchild of “Fargo” creator Noah Hawley, who brings an aesthetic style that’s “Wes AndersonStanley Kubrick: bright, symmetrical, futuristic but kind of retro,” says co-star Rachel Keller.

The 25-year-old actress, who starred in “Fargo” Season 2, followed Hawley to his latest FX series, as did Jean Smart and much of that crew. Here, Keller plays Syd, a new patient at the hospital who becomes David’s girlfriend — despite her strict aversion to physical touch. It’s she who guides David to Melanie Bird (Smart), a therapist whose unconventional team of specialists open his eyes to the abilities — including telekinesis — he didn’t know he possessed. Also influential to David is his friend Lenny (Aubrey Plaza), a fellow psychiatric patient convinced her luck is about to change.

“Syd and Lenny are almost the good and bad angel on David’s shoulder. There’s a mischievous, dark quality to Lenny … Aubrey portrays that very well,” Stevens tells The Post. “There’s a deviousness to the plot as soon as she appears. Stuff is going to get a little crazier. But there’s also a dawning realization that’s it’s perhaps not quite as clear-cut as he thought it was.”

That’s a function of the work David begins to do with Melanie — reexamining his past to search for answers about the origins of his mutant powers that forms the focus of the show’s eight-episode first season.

“This installment is mostly about going back and discovering David’s memory,” Keller says. “The characters play roles in that journey for him because there’s a pressing matter at hand that needs to be addressed ... So there’s room to grow with all the characters [in future seasons], including Syd.”

“Wes Anderson-Stanley Kubrick: bright, symmetrical, futuristic but kind of retro.” — “Legion” co-star Rachel Keller describing the new series’ look.