Emma Stone’s Cruella de Vil is a supervillain with a believable backstory – born Estella, bullied by boys at school and established as a maverick who’s always refused to “follow the pattern” (as her single mother puts it) in both dressmaking and in life.

Set in 1970s London against a backdrop of the emerging punk scene, this playful prequel by Craig Gillespie (I, Tonya) is a fine feat of world-building. Like Phantom Thread or Marie Antoinette, it’s also an excellent fashion film, playing on the myth of the egocentric, detail-oriented genius. One of its main narrative threads involves Estella’s apprenticeship at, and eventual sabotage of, a couture fashion house headed by an icy narcissist named The Baroness (Emma Thompson, exuding Meryl Streep’s energy in The Devil Wears Prada). Fashion enthusiasts may also draw connections between the House of Baroness’s sculptural, Dior-esque gowns and Estella’s Alexander McQueen-influenced lace and leather looks (McQueen, of course, succeeded John Galliano at Givenchy in the 90s when the latter moved to Dior). There is even a reference to McQueen’s 2011 monarch butterfly dress.

Cruella is presented as a rebel — impatient, perpetually misunderstood and unwilling to play by the rules of a world that casts her aside at every turn.

Cruella is already a mischief maker when we first meet her as a young girl named Estella. Her loving mother tries to put her on the straight and narrow, but after a series of tragic events, Estella is orphaned and left to fend for herself on the streets of London. A few years later, Estella, now played by Emma Stone, is a seasoned grifter committing robberies with her buddies Horace and Jasper. (They’re played by Paul Walter Hauser and Joel Fry.)

Estella has an extraordinary eye for fashion; she sews amazing disguises for herself and her partners in crime, with a bit of inspiration from a vintage store owner, Artie, played by John McCrea. Before long, Estella lucks her way into a job as a designer for the Baroness, an imperious queen of couture who runs the most exclusive fashion label in London.

As the Baroness, the great Emma Thompson gives a performance of diabolical wit — she’s half wicked stepmother, half Miranda Priestly from The Devil Wears Prada. The Baroness brings out a madly competitive streak in Estella, who soon unleashes her pent-up alter ego, Cruella, as a kind of glam-punk performance artist of the fashion world.

Determined to upstage her nemesis while still guarding her secret identity as Estella, Cruella begins crashing the Baroness’ galas and parties in attention-grabbing gowns — the work of the brilliant costume designer Jenny Beavan, in her biggest showcase since Mad Max: Fury Road.

The Emma-vs.-Emma matchup is as irresistible onscreen as it must have been on paper. But their rivalry also points out a conceptual weakness in the movie, and perhaps in the ongoing trend of trying to recast villains as sympathetic antiheroes. Thompson’s Baroness is flat-out monstrous in ways that put this Cruella to shame. In a movie that’s supposed to be about the rise of a great villain, the Baroness turns out to be the actual great villain.

Nonetheless, Stone gives it her all in a tricky role with echoes of the lowly young woman turned ruthless schemer she played in The Favourite. Here, she’s frankly more interesting as Estella, smartly biding her time and plotting her next move, than she is as Cruella, who is often upstaged by her own wardrobe. Is Cruella meant to come off as misguided, unhinged or genuinely unscrupulous? The script tries to suggest a complicated mix of all three and winds up feeling mostly confused.