The point of interest is the Gastric Acid attack. For a colorless, you do 20 damage and if your opponents active Pokemon has an ability, it's shut down until the end of your next turn. Now I could see this being a solid counter to Trevanant of the same set. Shut off the item lock ability and allow yourself to play items next turn. Outside of that, I'm not sure. I'm struggling to come up with ability pokemon that aren't bench sitters. You could hit a Darkrai and force them to waste energy to retreat next turn, but a lot of good that's going to do if they have another Darkrai Also, since a lot of Darkrai decks use Garbodor, it's not going to matter anyway. Then there's Lugia. If you hit that with this, you could deny your opponent an extra prize. Empoleon is another one (diving draw) and maybe Genesect would be stopped from using a red signal.
But for the most part, I just can't think of any practical uses outside of the hard lock decks. And even there, it's a questionable counter. What happens if the Keldeo / Float Stone out of it? Does Arbok's effect go away? Then there's what happens if you're opponent has multiple pokemon with the same ability and they retreat into a new one. In that case, you're pretty much screwed.
I'm rambling, but overall, I like attacks like this, but I'm very skeptical if this is going to be very useful. It's a shame they couldn't make it like Team Rocket's Arbok and let you snipe the troublesome pokemon.
