How often do writers want or attempt to reuse special abilities/super powers that have shown up in other works but those characters are dead or no longer used? Is that frowned upon? I think of stuff like some of the mutant powers in X-Men 2099 and other imprints no longer in print. Some times I think it'd just be cool to reuse something like that if not the character cuz otherwise a really cool power will just go to waste.