I think it's probably best to consider Prometheus less an actual character than a plot device to up the stakes significantly. That's fine, comics live from their big explosions and oh shiiit moments, but it has to be used with care or it becomes unbelievable, boring or just plain silly. None of the second Injustice Gang had all that much character, they where basically just tools in Luthors fight against godlike people he didn't care for very much. Human sized Atom Bombs for Lex to chuck in Superman's general direction. That's probably how they're used best.