Later, Lysandre was still persistent to continue the fight, despite having heard about the destruction of Team Flare's control machine. In the following episode, Gyarados fired off its Hyper Beam, only to be dodged by Pikachu. It was then hit in succession by a Quick Attack, Cut, and Dragon Claw and was finally defeated by Pikachu's Thunderbolt.
Very little is known about Gyarados's personality as it was only seen during battle against Ash and Alain. It has been shown to be very powerful, being able to withstand multiple hits from Ash's and Alain's Pokémon and defeat four of Ash's Pokémon on its own.
At Lysandre Café, Gyarados was used to scare Trevor before being stopped by Diantha, who had her Gardevoir Mega Evolve to make it back off. Later, Lysandre talks to Gyarados about how it will be able to one day Mega Evolve now that he has its respective Mega Stone.
When X attacked the Team Flare Secret HQ, Lysandre used Gyarados to battle him and Mega Evolves it. With Lysandre's Mega Ring, which had its Key Stone stolen from Korrina, Gyarados can Mega Evolve into Mega Gyarados.