>>21154447>>21154459>beautiful defensive type combo>assload of defensive/support moves>reliable recovery>clears hazards>removes status>powerful Fairy STAB>one of the best setup moves in the game if you feel like cheesing shit with what is basically a Fairy-type recoil-free Selfdestruct>very usable coverage movepoolAssuming a very probable 75/110/110/110/105/80 base stat spread, this thing will have plenty of room in OU. Mostly for defensive reasons, though as others have pointed out, Pixilate STABs hit really fucking hard.
Mega Altaria is probably the second best looking ORAS Mega so far, after Mega "Oh God Quickban it Now" Salamence.
And if it picks up one of three Very Important Egg Moves, well... 