Writer-director James Gunn’s “Superman” was always going to be a strange chemistry of filmmaker and material. Gunn, the mind behind “Guardians of the Galaxy” and “The Suicide Squad,” has reliably drifted toward a B-movie superhero realm populated (usually over-populated) with the lesser-known freaks, oddities and grotesquerie of back-issue comics.

For the last 20 years, the predominant cinematic image of Superman has been one of a Christlike martyr sent to Earth to suffer for the sins of a world he does not belong in and can never fully understand.