Warning: Major Spoilers For Legion seasons 1-3 ahead.
Who is Aubrey Plaza’s Lenny Busker in Legion? The FX series tells the story of David Haller, son of Charles Xavier and one of the most formidable mutants on the planet. While the series is X-Men adjacent, Legion is very much a unique take on the superhero genre. David’s story was adapted for television by Noah Hawley, the mind behind another excellent FX show, Fargo. Legion is currently airing its third and final season.
Dan Stevens stars as David, who suffers from schizophrenia - or at least that’s what he’s been told. The truth is that David’s mutant abilities, such as telepathy and telekinesis, made him feel like he was going crazy. In reality, (though Legion makes viewers question exactly what that is) he’s just unbelievably powerful. By this point in the series, David has been a confused victim, a reluctant hero and perhaps most surprisingly, the villain of his own story. Legion is always evolving, but one constant across all three seasons has been Aubrey Plaza’s character, Lenny Busker.
David’s close friend and confident, Lenny was created specifically for the TV show. Lenny and David met when both were patients at Clockworks Psychiatric Hospital, although his often unreliable memories might have had viewers believing otherwise. The version of Lenny that fans were introduced to in “Chapter 1” met her apparent end that very same episode. Lenny wound up fused into the walls of the asylum, an unfortunate casualty of David and Syd accidentally switching bodies and Syd being unable to control his immense powers. Not long after, Lenny began appearing to David. However, this wasn’t really her, at least not exactly. Her consciousness had been absorbed by Amahl Farouk, a mutant parasite who’d taken up residence in David’s mind. David had assumed that he was talking to his dead friend, but in reality, he’d been manipulated by the Shadow King all along.
The Shadow King was later driven out of David’s head, but found a new host in Oliver Bird. Trapped by the mutant within the astral plane, Lenny tried to bargain her way into a new body. Eventually, this request was granted, though at a horrible price. The Shadow King murdered David’s sister, Amy, and fashioned her into an almost perfect replica of Lenny. This new iteration of the character is the closest that fans had come to seeing the real Lenny for quite some time. After being trapped in some form or another since the show began, she was finally granted some freedom, though it came at the cost of Amy's life. Despite the circumstances, Lenny was able to find some measure of happiness.
Legion season 3 found Lenny back at David’s side, as his number two in his very own commune. She and her true love, Salmon, were happy and expecting a child, but Lenny was torn between that and her duty to help David realize his plans.
Thanks to David's ongoing war with the Shadow King, Lenny was left shattered after time-traveling shenanigans in the previous episode forced her to live through the entire life and death of her unborn child, as well as the demise of Salmon. When David ignored her pain in favor of pursuing his own agenda, even offering to take away her memories of the incident, Lenny chose to release herself from his control once and for all by taking her own life. This was a tragic end for the fan-favorite character, though she did end things on her own terms.
However, death isn’t always permanent in the world of Legion and it certainly hasn’t been for Lenny in the past. Fans will just have to wait to see if Aubrey Plaza’s character will return.