Alain's Charizard began as a Charmander from Professor Sycamore while Alain assisted him. It evolved into Charmeleon and then Charizard after losing to Lysandre's Pyroar, an event where Lysandre gifted Alain Charizardite X and a Key Stone.

This Charizard displays pride in battle strength and mirrors Alain's dedication. It shares deep trust with Alain but shows unease during deception, like when Alain withheld truths from Mairin, indicating an inherent moral code beneath its fierce exterior.

In combat, Charizard achieves its first Mega Evolution against Astrid's Mega Absol. As Mega Charizard X—marked by black scales and blue flames—it overpowered Absol with Dragon Claw and Blast Burn. It later defeated Dragon Tamer Remo's Mega Garchomp using its Mega-Evolved Dragon advantage and lost valiantly to Siebold's Mega Blastoise, earning the Elite Four member's respect.

Through escalating conflicts, Charizard battled Steven Stone's Mega Metagross to a draw before Lysandre intervened. Against Primal Groudon during the primal crisis, it endured Precipice Blades, sustaining injuries that dimmed its tail flame. Under Lysandre's command, it survived a gauntlet against ten Mega-Evolved Pokémon—including Malva's Mega Houndoom—through sheer endurance.

Later, Charizard aided Team Flare's capture of Zygarde (Z-2), clashing with the Legendary Pokémon via Dragon Claw and weathering Land's Wrath. It developed a rivalry with Ash's Greninja, winning their first battle using Blast Burn against Ash-Greninja and fighting to an incomplete conclusion when Ash collapsed mid-second clash.

Charizard secured Alain's final Kalos Gym Badge by defeating Korrina's Mega Lucario. Its power grew through relentless battles, aligning with Charizard traits where adversity intensifies its flames, showcasing continuous growth and an unwavering bond with Alain.