I know this thought is dumb/crazy (I blame my tired brain), but what about the games themselves? Like each generation is based around a duo of conflicting or complementary opposites (generally with a third thing like Land and Sea having Sky). They have quite frankly checked off all the big important world shaping stuff. Of course I'm tired as **** right now and just rambling whatever is coming to mind so I'm probably missing something. Like they haven't done anything with Normal, Rock, Grass, and Bug yet. And I know the last three can form a trio going with the Mineral, Vegetable, and Animal Kingdom Triad so there is that.
Anime idea: I vote for Ash to be a teacher. And he doesn't do the formal league challenge instead he fights the gym leaders to test their skills and makes sure they're qualified for their jobs after Geeta requests him too because reasons I can't think of right now.