Altaria

Mega Altaria is an impressive anti-metagame threat, boasting a gigantic number of resistances and defensive utility to go along with its already great bulk, thus allowing it to counter and force out a large number of Pokemon in OU. It is no slouch offensively either; in fact, with Pixilate and Fairy STAB, it is deceptively powerful, moreso than established powerhouses such as Azumarill, Mega Gyarados, Mega Gallade, and even Kyurem-B. This is further amplified by Altaria's access to Dragon Dance, as well as a wide physical, special, and supportive movepool, giving it a degree of flexibility and unpredictability.

Mega Altaria's only real flaw is its base 80 Speed, which is quite below average by ORAS OU standards, making it somewhat easy to revenge kill even when boosted. It is also occasionally plagued by four-moveslot syndrome; if it lacks a certain move, it can easily be taken advantage of by common checks and counters. Finally, by virtue of being a Mega Evolution, it cannot hold useful items such as Lum Berry, Pixie Plate, Life Orb, and Leftovers, which downplays its overall offense and defense quite a bit. With all that said, don't be fooled into thinking that those cons hold Mega Altaria back in a significant way; it's a downright ruthless Pokemon to face off against.