Pokemon XY: Mega Evolution

Alain and his Charizard are on a mission to seek out and challenge Mega-Evolved Pokemon! They battle and defeat Astrid and her Mega Absol, unaware that they’re being watched. The observer is a young Trainer named Mairin, who’s just started her journey with her Chespin—and who has a lot of questions about Mega Evolution! Alain tells her he doesn’t have all the answers, but she’s still asking questions when he gets a call and has to leave. She follows him to a cave, where he finds a Mega Stone. When he emerges, he’s challenged by Dragon Tamer Remo and his Mega Garchomp—with the Mega Stone on the line! Alain wins again, and afterward, Mairin tells him that she wants to learn to use Mega Evolution, too. But first, she’ll have to catch some more Pokemon! Alain helps Mairin catch a Flabébé, and then he disappears when she takes it to a Pokemon Center. Nurse Joy tells Mairin that he went to a nearby restaurant to challenge the owner, Siebold of the Elite Four, and his Mega Blastoise. Mairin catches up just in time to watch the battle! The type disadvantage is too much for Charizard to overcome even after it Mega Evolves, and Alain is defeated—but Siebold is impressed with his strength. After the battle, Alain continues his journey, and Mairin is determined to go along with him and find a Mega Stone of her own!

Landing in Hoenn, Alain and Mairin walk down a foggy mountain. The duo encounter Steven Stone, whom Alain challenges in a Mega Evolution battle. Steven accepts, taking out his Metagross. The two Mega Evolve their Pokemon, and fight a worthy battle. While Mega Metagross and Mega Charizard X are about to finish each other off, a Pyroar unleashes a Flamethrower and interrupts the two. The Pokemon belonged to Lysandre, a businessman who owns a lab in the Kalos region. He is revealed to be Alain's boss, and Alain tries to shut Mairin out of his affairs. In a flashback, Alain contacted Professor Sycamore about Charmander's evolution to Charmeleon. He was trying to find a Charizardite in some ruins and encounters Lysandre, who proposes him a deal- a Charizardite in exchange for his help. Before leaving, he tells Alain that he has to be the strongest. Back in the present, Alain and Mairin follow Lysandre and Steven up to Mt. Pyre. Steven reveals that he traveled in search of stones as he was interested in Mega Evolution. He and Lysandre show to each other two different wooden tablets. One half shows the location of the gate and the other half shows the way to open it: a Mega Stone. Both Trainers take one pillar, revealing a stairway that leads to the mountain. At the top, they find some ruins in search of the Giant Rock. Steven and Alain find two dayes and activate them, revealing a crystal. The group finally found the Giant Rock. Lysandre talks in his communicator, and a helicopter flies in. A science team starts researching the power of the Giant Rock, and in the process the sky turns dark, and Rayquaza appears. A sudden glow engulfs it, and it Mega Evolves into Mega Rayquaza, awakening Groudon and Kyogre. Mega Rayquaza is in a rage, destroying everything in its path. Alain and Steven take out and Mega Evolve their Charizard and Metagross. Mega Charizard X fails to use Flamethrower against Rayquaza, and Metagross fails to attack as well, and Rayquaza counters with Draco Meteor. It then flies away. The ruins are destroyed, Alain is injured, and the Giant Rock is gone. With Rayquaza on the loose, Lysandre instructs Alain and Mairin to head to Rustboro City and investigate there, with Steven tagging along. In secret, he instructs Alain to stay close to the Champion, as his knowledge is useful.

When a clash between Primal Groudon and Primal Kyogre causes Rayquaza to stir, Alain must find a way to stop these titans before they bring the Hoenn Region into ruin.