So I used it in X and Y and I swept like 100 people (literally) with this thing 6-0!
The set used:
Item: Life Orb
EVs: 252 Atk/252 Spd/4 Hp
Adamant Nature (should I make it Jolly?)
Can it be used effectively in the ORAS metagame considering it is a whole new one?
Depends on the team you are against and how good the player is. Honestly, I can't see how that set worked in X/Y, but basically, Talonflame and Lando-T are still running around, so I can't see Toxicroak being in a team without being outclassed.