az is the roaming legendary, you must battle him and defeat him, go to where you caught xerneas/yveltal and he is there, you talk to him and he walks away saying "My home was once within the flowers...", once you do that you find a crowd in the middle of Lumoise City, AZ is perched on the top of the tower and jumps and turns into the roaming griffin-like flower pokemon.
It's Grass/Dragon
believe me or not, your choice.
