Marvel’s X-Men comics sometimes led with a cheeky fake-out to tease the reader. We open in media res, our mutant heroes pitched in desperate battle against some foe. They’re battered and bruised. They’ve suffered casualties. And right before the moment of defeat, when all is seemingly lost, the scene fades away, leaving the super-powered faculty panting in an empty steel-blue hangar. It’s the Danger Room, the mansion’s holographic training facility. Cyclops, Iceman and co. were never in danger; the stakes weren’t real. X-Men: Apocalypse, the third film in the franchise’s origin reboot, is one long Danger Room scenario, a frictionless…