>>28100132What we need is variation, not customization, meaning:
Pokemon, like animals in reality, should have variants of themselves based on the region and season where they live. We are already seeing this with the introduction of Alolan formes of Pokemon. It's a first step, though a drastic one going as far as changing the types entirely of some pokemon.
I personally feel that there will never be implementation of variants among pokemon, as nice as it would be. We'll probably just have to be thankful for shiny pokemon.
As for customization, I feel that the best route for this is for whatever item your pokemon is holding to be shown. If you want to go further, then there should just be some accessories to attach.