ok so i'm not sure if this has any relevance whatsoever to actual battling, but when I send in a Pokemon, there are some of them like milotic, samurott or Kyurem there is a sort of cloud thing that poofs out on their side of the battle field, & it looks similar to part of the rock slide animation. It has always made me curious to what this is & it only ever happens to one Pokemon at once, like if I sent in Kyurem against a mitotic, only the kyurem would make the cloud. I think it might be related to the weight or size of the Pokemon but I don't know.
Thanks