Arceus Grass could be a bitch to the team if it had perish song or t-wave. other than that looks pretty solid. Also Liked this team demolishes Sand Abusers already, what I would change though it's Giratina's set.
Giratina-O @ Griseous Orb
Trait: Levitate
EVs: 212 Atk / 252 Def / 44 Spd
Adamant...