Lysandre sent his Shiny Gyarados to battle against Ash and Alain along with his Pyroar. Then, Lysandre Mega Evolved it and sent it into battle. Gyarados fired Incinerate, along with Pyroar's Incinerate. However, both attacks were countered by Ash's Pikachu's Thunderbolt and Goodra's Dragon Pulse. Alain's Mega Charizard tried to use Dragon Claw, but was stopped by Mega Gyarados' Stone Edge. Once Pyroar was defeated, Lysandre continued the battle with Mega Gyarados. Mega Gyarados continued attacking, by repelling Ash's Noivern's Boomburst and Pikachu's Thunderbolt with Hyper Beam. It proceeded to attack Pikachu with Dragon Tail, but Noivern took the hit and was defeated. Alain's Charizard used Dragon Claw, along with Hawlucha's High Jump Kick, to wound Mega Gyarados. Mega Gyarados retaliated and bashed Hawlucha on the floor, defeating it as well, then fired Hyper Beam. Alain's Mega Charizard hit Mega Gyarados with Thunder Punch, as did Goodra with Dragon Pulse. Mega Gyarados defeated the latter with Hyper Beam, so Ash-Greninja and Talonflame were sent to attack with Cut and Flame Charge. Mega Gyarados repelled them with Stone Edge, so Alain's Mega Charizard caught both of them. Immediately after, Mega Gyarados slammed them with Dragon Tail, which made Talonflame faint. When Gyarados tried to blow its remaining opponents off the tower with Hyper Beam, Malva's Houndoom blocked it with Flamethrower when Malva turned against Lysandre. Mega Gyarados fired Incinerate which Greninja countered with Water Shuriken. Mega Gyarados tried another Hyper Beam but Pikachu evaded the attack and hit it with Quick Attack. With Mega Charizard's Dragon Claw, Ash-Greninja's Cut and Pikachu's Thunderbolt, Mega Gyarados was finally defeated and reverted to its original form.