Can.....can we please not have pokemon fusions? It was cool when Digimon and Dragonball did it ten years ago, but it sort of doesn't mesh well with my idea of what pokemon is supposed to be.
It's similar to the reason I don't think Digimon with multible didgimon works, digimon has always been about the friendship and strong unique connection between the digiknight and their digimon. That doesn't really work as well if each digiknight has multiple digimon.
Not to say that Pokemon doesn't have elements of those themes as well but in the end it's about collecting, catching them all and building the best team possible, with many pokemon disregarded to the pc either immidiately after they get cought of after a very small amount of time. This even applies to the anime, Pikachu is basically the only pokemon Ash still has with him from the very beginning, most of the older ones get sporadic appearances at best. the concept of fusion just doesn't mesh well with that imo.