yeah, I've found a great counter to eviolite pokemon is mean look umbreon. It can mean look them, then stall them to eternity with toxic (because they don't have leftovers) an posibly set up on them. Here's the moves and Evs:
Umbreon@careful
252 hp 252 sp def
Leftovers
Mean look-traps the pokemon in question
toxic-gets a toxic on them quickly
protect/curse- stall out toxic and your own leftovers, or get a free setup on umbreon. The problem i have with this is chansey's s tosses will eventually wear it down, but a free +how ever much is very tempting.
payback-gets boosted by curse, stops you from being taunt bait otherwise
Other options: you could use torment to prevent them from recovery stalling or hitting you a lot.
if you feel like it, you could add some more def at the cost of sp. def. However, most eviolite users (pory 2 especially) have special attacks, so this makes it more capable of taking their attacks. Just watch out from catching a toxic from pory 2 or dusclops.
Good luck!