So where do you go when all avenues explored with character and theme? You start tearing down the previous work. Good Fanfiction is a model for this. Harry Potter and the Methods of Rationality good example. Responds to the work by telling a new story while analyzing the nature of the old one, in this case by picking apart the nature of Wizard society. Hell, it’s what Watchmen did to comics in the first place.
HP:MoR is now not merely “fanfic”, but an example of deconstruction-by-example: