in the games current state a major part of the late game meta is gems and crystals, however they aren’t balanced too well between different Pokémon
probably the main concern that comes up all the time is that several types can have their crystals and gems activated with the clear rock, which is always active, while others must rely on rocks that only function when the weather is clear making them far less viable.
the second main issue is some dual type mons can be effected by 2 crystals instead of one, this makes them far better and with some of these mons, such as the very popular noivern, also getting their buff in clear weather.
so how do I think this should be fixed?
well for one no type being buffed in clear weather would be a simple fix for the first issue, maybe not ideal but it would certainly help, and the second issue I feel could be solved by pokemon only being effected by the crystal of their primary type, or the type displayed first in the pokedex.
I feel these changes would help balance the current meta and make noivern stop going supersaiyen.
additinally I think adding custom weather changing moves for the new weathers that are in the game is a good idea, we already added the weathers, why not finish them up? though I’d understand if this idea isn’t as popular.