What I would do is make each and every pokemon unique. I would have height differences visible in battle, along with color hue variations like stadium and a shaped (Like a star or a heart) birthmark on a random part of each pokemon, basically like spinda but for all pokemon.

I would also introduce a Sound-Type just for the sake of balance. It would be weak against Bug, Grass, and Ice and strong against Water, Steel, and Fairy

Aand thats not all, I would retcon the megas of weak pokemon (Like mawhile) into full blown evolutions

alsooooooooo would have the team focus on making the battles look absolutly spectacular (like pic related) rather than making a new battle gimmick