Pokémon Trainer Classes
This is probably the most pie in the sky idea. As we get to the 8th generation of Pokémon, the series is just bound to be running out of ideas. The creatures and their types can only vary so much, and it’s a kind of insane balancing act. A cool twist would be making the trainers themselves have more of an effect on how the Pokémon evolve. The best way to do this would be that trainers have various classes themselves that affect things about the Pokémon both in and out of battle.
How would that work? There would be a number of ways. Certain trainers could be better with certain types, maybe give XP or stat boosts. Maybe a certain class is the equivalent of a bard, granting buffs and debuffs throughout a match by cheering (or even singing) for their team in battle.
It’s potentially a big changeup to the standard formula, but not one that would drastically change the core of what Pokémon is. It would add a whole new layer of strategy to the game and be a super exciting new element for fans that may have dropped off after playing too many entries that have seemed too familiar.