I think this has been done before BUT a world where the superhero/villain scene is a kink thing. Traditionally, the hero is the top and "wins", though "gritty" pairs with villain tops are more common these days.
In addition to the usual "thing to put in holes" sex toys, super kink shops sell all sorts of macguffins to steal from each other, like remotes, self-destruct buttons, "ancient" gems and crystals, serums, and the like
There's a rise in villain/villain couples, but not a match in hero/hero ones, mostly because nobody's been able to figure out the logistics. Not to be confused with the league of evil/super team construct, which is more of a casual sex and occasional swinging arrangement.