Primal Reversion

Primal Reversion (ゲンシカイキ Primal Reversion in Japanese) is a devolution method introduced in Pokémon Omega Ruby & Alpha Sapphire. This is similar to Mega Evolution, except that the Pokémon devolve back into their ancient and original form, where they get the true power they once had. The only known Pokémon able to do this are Groudon and Kyogre. The primal reversion is represented with the symbol omega for Groudon and the symbol alpha for Kyogre.