My theory for how the Synergy stone is going to work is, like Pokken, each pokemon gets a 'gauge' in battle that maybe works similar to how it does in Pokken; where it increases the more damage they deal. I assume when that gauge is full the Pokemon gets a stat boost, and/or mega evolves depending on if it can or not.
As for mega evolution as it is now, I can see them retconning the mega ring in favor of this format, it makes mega evolving a reward instead of allowing people to spam the shit out of it like they used to be able to. As for how it works in meta, I don't fucking know, I'm a filthy casual. I guess its better than how it used to be.
