The League’s Katie Aselton joins X-Men spinoff series Legion

Actress Katie Aselton, who played Jenny MacArthur on the raunchy sitcom, has reportedly been cast as one of the supporting characters in Legion, and will play the older sister of the series’ protagonist, David Haller. Downton Abbey actor Dan Stevens will play Haller in the series.

According to EW, Aselton’s character is named “Amy,” and is described as someone who “does her best to remain positive, which proves difficult when her brother has spent years in and out of hospitals after being diagnosed as a schizophrenic.”

In the Marvel Comics universe, David Haller is the son of the telepathic leader of the X-Men, Charles Xavier. Although David inherits a mutant ability akin to that of his father, he’s unable to control his power and has frequently found himself at odds with the X-Men as his abilities threaten to destabilize the world around him.

The pilot episode of Legion will be written and directed by Fargo series creator Noah Hawley, who will also serve as an executive producer on the show. Hawley has indicated that the series isn’t likely to connect with the X-Men movie universe, despite the comic-book inspiration for the series and its links to characters in the X-Men universe.

Along with Stevens, Aselton joins a cast that already includes Parks and Recreation actress Aubrey Plaza as an optimistic friend of David, Designing Women actress Jean Smart as David’s therapist, Fargo actress Rachel Keller as a character named “Syd,” and unidentified characters played by Jeremie Harris (A Walk Among the Tombstones) and Amber Midthunder (Sunshine Cleaning).

The series is being produced by FX and Marvel Television, and involves many of the franchise producers of the X-Men movie-verse.

Legion is expected to begin filming soon.