There are two things that James Gunn does better than just about anyone else on the planet: One is making glossy mega-budget superhero movies that still march to the beat of their own drum (e.g. “Guardians of the Galaxy Vol. 2”), and the other is making over-the-top gore-fests so gross they straddle the line between indie cinema and outsider art. Gunn might be the only person to direct blockbuster tentpoles for both Marvel and DC, but he’s still the guy who co-wrote Troma’s “Tromeo and Juliet” at heart. And by the time the opening credits of “The Suicide Squad” are spelled out in the head blood that seeps from a supporting character’s freshly exploded skull, it’s clear that he always will be.

, Gunn’s deliriously ultra-violent “The Suicide Squad” wears the yoke of its genre with a lightness that allows it to slip loose of the usual restraints,...