“Okay,” to its benefit, takes each of these transformations equally seriously. It’s not really even a superhero story per se, though its seven-episode first season may be the introduction to one.

The series is adapted from a graphic novel by Charles Forsman (“The End of the ____ing World”) by the director Jonathan Entwistle and the writer Christy Hall. Entwistle was also behind Netflix’s “End” adaptation, and you see that show’s DNA in the bloody in-media-res beginning and the opening monologue, in which Sydney gives her diary a four-letter salutation.

Snarky and clad in a chunky sweater she wears like chain mail, Sydney got the diary from a school counselor as therapy for her anger issues. She has plenty to be mad about. Her father recently committed suicide. She, her mother and her little brother are living hand-to-mouth in a Rust Belt town where she knows few people and likes fewer. And her best friend, Dina (Sofia Bryant), by whom she’s plainly ensorcelled, has started dating a meatheaded jock, Brad (Richard Ellis).

Like the crime-spree tale “End,” “Okay” sees adolescence as a time of danger. Also like “End,” it centers on an alliance, albeit a less felonious one. Unmoored by Dina, Sydney strikes up a mutual sarcasm pact with Stanley (Wyatt Oleff), an affable weirdo and extremely small-time pot dealer who becomes her would-be boyfriend and, as her powers reveal themselves, self-appointed sidekick.

Lillis and Oleff are the two wires that give “Okay” its spark and tingle. Sydney may shop at the same vintage store as decades of alienated teens before her, but Lillis distinctively embodies her balled-up nerves and rubbed-raw discomfort in her own skin — when she says, “Sometimes I feel like I’m boiling inside,” the burn is palpable. And Oleff plays a familiar geek-neighbor species (Homo Briankrakowus) with a laid-back egolessness that pushes straight through nerdery into cool.