Exhaustis
This stuff started out as a by-product of a handy gizmo called the ‘AntiSom’ (invented by a gadgeteer about thirty years ago). The problem with being a nocturnal superhero — or even an after-work one — is, when do you sleep? For every billionaire playboy, there’s a dozen people with day jobs who can’t function on four hours’ sleep indefinitely. So the gadgeteer came up with the AntiSom; a rugged, reasonably foolproof device that would drain the exhaustion out of a metahuman. Fifteen minutes’ worth of use would do the work of eight hours of sleep; and with no long-term effects either, because super-powers.