Mega Rayquaza has been revealed for both Omega Ruby and Alpha Sapphire. It has been given the new ability Delta Stream, which is similar to the effects of Desolate Land and Primordial Sea in that it makes any abilities and moves that influence the weather fail to work. It also whips up strong winds, and causes moves of a type that flying-type Pokemon are usually weak to to only deal normal damage to flying-type Pokemon, which are unique effects of this ability. Mega Rayquaza is also given the new move Dragon Ascent, which is supposedly the most powerful flying-type move.
The inclusion of Rayquaza in Omega Ruby and Alpha Sapphire, versus not including it and making an Emerald remake, will help level out the playing field for the newly bulked up Kyogre and Groudon. Rayquaza is just as bulked up, receiving an increase in all stats, especially in Attack and Sp. Attack.
As for physical changes, Rayquaza receives black sections, with red spots, of its segmented body, and a razor-like appendage attached to its neck. It also receives several yellow streamer-like attachments on its body.
