Here’s what Warner Bros. and DC think we need: another superhero movie about an earnest young man suddenly forced to shoulder responsibility and fight for justice.

Here’s what we actually need: A superhero movie about a badass nana with a secret revolutionary past. Guess which movie “Blue Beetle,” premiering in theaters Friday, delivers?

However, credit must be given for including a rebel grandmother, who, though not the movie’s titular superhero, is one-fifth of the lovable Mexican family that enlivens this paint-by-numbers superhero film, directed by Ángel Manuel Soto and written by Gareth Dunnet-Alcocer.

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The actual protagonist is Jaime Reyes (Xolo Maridueña), a fresh-faced college graduate who arrives home to find his family struggling financially. Reyes is fruitlessly casting around for a job until he meets Jenny Kord (Bruna Marquezine), the chic heiress of Kord Industries, a colossal tech company run by her great-aunt, Victoria Kord (Susan Sarandon). When Jenny hands Jaime a stolen scarab hidden in a fast-food box, Jaime discovers the beetle is a sentient piece of ancient alien tech that has a mind of its own. It fuses with Jaime, protecting him and granting him the ability to fly, heal quickly and create any weapon he imagines. As Victoria aims to recover the beetle to create armies of destruction, Jaime must prevent her from getting it and keep his family — and the world — safe.

“Blue Beetle” offers a formulaic narrative — so predictable, in fact, that you can catch the tragic death in Jaime’s hero origin story coming from three counties away. Other superhero benchmarks are also at play: the young man thrashing around while adjusting to his new powers; clunky battles that look like a big-screen re-creation of a 5-year-old’s BattleBots; hard-won moral lessons that are really clichés. (During a fight, Victoria’s brutal bodyguard declares, “The love you feel for your family makes you weak”; turns out Jaime’s familial love actually empowers him — who knew?) This unremarkable story, along with cheap-looking visual effects and Soto’s colorless direction, is a prime example of somnambulist filmmaking that lulls the audience into a mindless stupor.

At least the Reyes family is a force to be reckoned with; their chaotic ensemble scenes are the most delightful, and truly unexpected, of the movie. Jaime’s parents (Damían Alcázar, Elpidia Carrillo) buttress the hero’s emotional journey with mawkish dialogue, but there’s more to mine in Jaime’s sassy, blunt younger sister, Milagro (Belissa Escobedo), and her quips about the family’s race, class and social status. Uncle Rudy (George Lopez), with a beard recalling a raccoon tail, is a wild-card tech genius with enviable one-liners that Lopez delivers with perfect comic timing. (“Is that the new Tamagotchi?” he asks when the beetle first awakens.) And Nana, played by Adriana Barraza, is ready to steal the film.