Mega Gyarados (Pokémon GO) - Best Movesets, Counters, Evolutions and CP Mega Gyarados #130 (Kanto) Pokémon type Water Dark Evolution Mega Gyarados currently has no evolutions in Pokémon GO. Magikarp Gyarados 400 Mega Gyarados Evolving Mega Gyarados costs 300 Mega Energy the first time, and 60 Mega Energy every other time. Forms.