Latias

Latias's typing along with solid bulk makes it a great offensive check to a variety of OU threats, including Keldeo, Breloom, Manaphy, and Mega Manectric. This defensive utility, coupled with access to Defog, makes it an excellent choice for both offensive and balanced teams. On top of that, Latias's Mega Evolution is incredibly bulky, allowing it to serve as a reliable choice for support on defensive teams. Latias's main issue is that outside of its Mega Evolution and Healing Wish, it is almost entirely outclassed by Latios, which brings far more power to the table. It also finds itself walled by common Fairy-types, such as Azumarill, Mega Gardevoir, and Clefable, as well as Steel-types such as Klefki, Ferrothorn, and Scizor. Although Latias's Psychic typing brings a useful set of resistances, it also brings a weakness to Pursuit trappers, which access to Reflect Type can help nullify.