Alain met Charizard as a Charmander while he was still one of Professor Sycamore's assistants. Eventually, he took Charmander with him on his journey to find Mega Stones.
Later, Charmander evolved into Charmeleon sometime before Alain contacted Professor Sycamore. It battled Lysandre's Pyroar for an Ampharosite and lost. Some time after Alain received a Mega Ring and Charizardite X, Charmeleon evolved into Charizard.
Charizard made its official debut in Mega Evolution Special I where Alain sent it out to battle Astrid's Absol. Charizard began with Flamethrower while Absol countered with Psycho Cut. Afterwards, Alain Mega Evolved Charizard to Mega Charizard X while Astrid did the same to her Absol. Charizard then used Steel Wing and clashed with Absol's Megahorn. After withstanding a powerful Dragon Claw and Flamethrower, Absol fired off its Dark Pulse. Charizard then countered with Blast Burn which overpowered the attack and defeated Absol. After the battle, Charizard sat with Alain by a flowing river.
When Alain went to some ancient ruins, he battled Remo’s Garchomp, Garchoo, using Charizard. Both sides immediately Mega Evolved their Pokémon. Charizard took a hit from Remo's Garchomp's Dragon Rush, but quickly recovered and fired off a Flamethrower. Both Pokémon then flew up and kept clashing using Dragon Claw and Dual Chop, causing both to fall down. As the smoke cleared, only Charizard was left standing, giving Alain the win.
Later, Charizard went up against Kalos Elite Four member Siebold and his Blastoise. After Mega Evolving, it flew towards Blastosie and used Dragon Claw, while dodging Blastoise's Hydro Pump. Blastoise, however, countered the attack with Skull Bash. After Blastoise Mega Evolved as well, Charizard charged in using Steel Wing, but was hit hard by a Mega Launcher-powered Dragon Pulse. Charizard was then hit by Hydro Pump, but it quickly recovered and used Flamethrower. Flamethrower, however, was cancelled out by Blastoise's Power-Up Punch, but Charizard managed to stab Blastoise with a powerful Dragon Claw. Blastoise, however, was able to withstand the attack and used another Dragon Pulse to defeat Charizard.
In Mega Evolution Special II, Charizard fought Steven's Metagross. It Mega Evolved into Mega Charizard X and launched a Flamethrower which was countered by Metagross's Psychic. Metagross then Mega Evolved to Mega Metagross. Despite having a type-advantage, Charizard was overwhelmed by Metagross's attacks, while its attacks didn't seem to faze Metagross. After taking a Flash Cannon, Charizard hit Metagross with Dragon Claw. Metagross, however, wasn't fazed and struck Charizard with a powerful Meteor Mash, crashing it into a cliffside. Charizard was able to emerge from the stones and went for its Blast Burn. Surprisingly, Metagross had withstood the super-effective attack. When both sides went for Dragon Claw and Meteor Mash, Lysandre's Pyroar interrupted the battle with Flamethrower.
While Alain, Mairin, Steven, and Lysandre were in some ancient ruins and Rayquaza attacked, Alain sent out Charizard alongside Steven's Metagross. After Mega Evolving, it launched a Flamethrower and a now Mega Evolved Rayquaza quickly evaded the attack. Charizard got attacked by Rayquaza's Dragon Ascent and fell. Steven's Metagross tried stopping the fall, but Rayquaza's Draco Meteor forced the group to take evasive action.
In Mega Evolution Special III, Alain sent out Charizard to protect the Giant Rock hovering over Primal Groudon and Primal Kyogre, and immediately Mega Evolved it into Mega Charizard X. Mairin took notice of Charizard and so did Groudon. Groudon started with Solar Beam which Charizard easily dodged. Steven's Metagross joined in and fought Kyogre as Steven pointed out to Alain that he could not protect the Giant Rock alone with Charizard. Charizard scored a hit with Flamethrower while Groudon countered with Precipice Blades. Charizard was able to dodge them all and destroyed the last one with Dragon Claw.
When Groudon attempted to reach for the Giant Rock, Charizard stopped it by using Steel Wing on its hand. Despite covering Groudon with smoke, it was able to use Precipice Blades again and this time, landed a hit on Charizard. Charizard was dealt tremendous amount of damage from the Precipice Blades and was sent crashing onto some ice earlier created by Kyogre's Ice Beam. Alain ran to see if Charizard was okay and recalled it before the flame on its tail went out completely.
Charizard was later seen in the episode battling a Trainer's Mega Tyranitar, while being observed by Lysandre.
In Mega Evolution Special IV, Alain sent out Charizard during his battle against ten Mega Evolution Trainers. Charizard took on a Mega Venusaur first. Both Pokémon Mega Evolved and Charizard started things off with Flamethrower. Despite the clear type advantage, Venusaur was unfazed because of its Thick Fat Ability. Charizard began to struggle as it was poisoned by Venusaur's Venoshock and held down by its vines. As Venusaur was about to finish Charizard with Seed Bomb, it used Dragon Claw which sliced through the Seed Bomb and took Venusaur out. Charizard was given a Pecha Berry after the first battle.
Since then, Charizard battled a Trainer's Mega Alakazam, Mega Heracross, Mega Scizor, Mega Ampharos, Mega Aggron, two other Pokémon off-screen, and Mega Pinsir, and defeated them each in succession.
After clearing nine Trainers, Alain and Charizard dealt with Malva of the Elite Four and her Houndoom as the final Trainer. After Mega Evolving, Charizard was surprised by the Dark Pokémon as its Flamethrower was initially absorbed by Houndoom's Flash Fire Ability. Afterwards, Houndoom Mega Evolved and put Charizard on the defense with a strong Flamethrower, and when Charizard attempted to counter by taking to the sky it got pinned down by Houndoom's Smog. Charizard released itself with Flamethrower and went on the offense with Steel Wing, which Houndoom countered with its horns. Houndoom then pinned Charizard to the ground with its Crunch attack, but Charizard freed itself with a Flamethrower (which Houndoom was no longer immune to) and then blocked Houndoom's Crunch with Dragon Claw. As Houndoom went to finish it off with Crunch, Charizard used its final strength to execute a Blast Burn which managed to score a direct hit, defeating Houndoom and winning Alain the battle.
After Alain left Lysandre Labs to help Mairin's Chespie wake up from its coma, Charizard battled a Trainer's Mega Banette.
In the main series
Charizard made its main series debut in A Meeting of Two Journeys!, where it was first used to save Ash's Pikachu from Team Rocket and saving him from a nasty fall as well. It was then used in a battle against Ash and his Greninja. Charizard was able to hold the upper hand despite a type-disadvantage, destroying Greninja's Water Shuriken with Dragon Claw, and dodging Greninja's attempts to hit it with Cut. It retaliated with Flamethrower, hitting Greninja. Afterwards, Charizard Mega Evolved and attacked with Dragon Claw, although Greninja countered with Cut. Greninja attempted to confuse Charizard with Double Team, but it countered by destroying all the copies with Flamethrower. Greninja then attempted to hit Charizard with a surprise Aerial Ace, but Charizard revealed its newly learned Thunder Punch to knock Greninja away. Greninja tried to retaliate with Water Shuriken, but Charizard proved to be faster and hit it with a second Thunder Punch. When the battle seemed to be over, Greninja transformed into its Ash-Greninja Form and managed get a good hit on Charizard. It, however, quickly recovered and used Thunder Punch, which Greninja blocked with Cut. Charizard was then able to break through Cut and finished Greninja off with Blast Burn.
In An Explosive Operation!, Alain used Charizard to battle Z2 in its 50% Forme that Team Flare was struggling with. Charizard was able to knock down Zygarde with a surprise Flamethrower and moved in for a powerful Dragon Claw, dealing some damage to the Order Pokémon. It then Mega Evolved and tried stopping an Extreme Speed from Zygarde, but Zygarde eventually overpowered it and knocked it into a crater. Charizard quickly recovered, however, and knocked Zygarde down with Dragon Claw. Zygarde tried to defend itself using Land's Wrath, and although Charizard was able to dodge the initial assault, it was eventually knocked into the distance. Charizard was ready to counterattack, but before the battle could continue Team Flare used their specialized weapons to take down the distracted Zygarde.
In The Synchronicity Test!, Alain used Charizard to have a rematch against Ash's Greninja. Similar to their previous battle, Greninja opened up with a Water Shuriken. Charizard skillfully dodged the incoming shurikens and struck Greninja with Dragon Claw. As Greninja went for Double Team, Charizard, like in their first battle, used Flamethrower to destroy its copies. This time, however, Greninja was able to hit Charizard from behind with a powerful Cut. Afterwards, Charizard signaled Alain its desire to Mega Evolve. Despite Mega Evolving, Greninja still proved to be a tough opponent, as it was able to overpower Charizard's Thunder Punch and kick it in the stomach with Aerial Ace. Charizard, however, was then able to grab Greninja's Cut and hit it with a close-range Flamethrower. After dodging another Water Shuriken, it hit Greninja with a powerful Thunder Punch. This, however, caused Greninja to transform into Ash-Greninja. With its increased power, Greninja was able to match Charizard in combat. After dodging Greninja's Cut, it proceeded to launch a Flamethrower. Greninja, however, blocked the attack with Cut and Charizard was struck from above by an Aerial Ace after its Thunder Punch was dodged. While clashing with Cut and Dragon Claw, Charizard used one of its claws to hit Greninja. Greninja, however, took the hit and dealt serious damage to Charizard with an immediate Cut, sending it flying backwards. The battle was called off when Ash collapsed from exhaustion.
During the introductory scene of Volcanion and the Mechanical Marvel, Charizard was shown battling Korrina's Mega Lucario at the Shalour Gym, as a Mega Charizard X. At the end of A Diamond in the Rough!, it was shown defeating the Gym Leader's Pokémon, winning Alain his eighth Badge and allowing him to qualify for the Lumiose Conference.
In A League of His Own!, Charizard was used to battle Trevor's Charizard in the first round of the Lumiose Conference. Trevor's Charizard opened with Fire Spin, which Alain's dodged by flying in the sky, retaliating with Flamethrower. Trevor's Charizard, however, blocked the attack with Dragon Claw. Trevor then revealed his Key Stone and Mega Evolved his Charizard into Mega Charizard Y. Upon Mega Evolving, Mega Charizard Y's Drought Ability activated, creating harsh sunlight and powering up all of its Fire-type moves. Alain's Charizard, however, was still able to block and dodge its opponent's attacks, creating a water shield by slamming its tail into the nearby stream to block an incoming Heat Wave and then flew up to dodge a Dragon Tail. It then Mega Evolved as well and countered a Fire Spin with Flamethrower, creating a cloud of smoke. Trevor had his Charizard fly into the sky, but Alain's was able to spot it through the smoke and defeated it with a single hit from Flamethrower. Charizard then proceeded to easily defeat Trevor's Aerodactyl and Florges as well, giving Alain the win and allowing him to advance to the next round.
In Analysis Versus Passion!, Charizard was Alain's second Pokémon during his semifinal match against Remo. It was shown easily defeating Remo's Rhyperior with a Dragon Claw. It then faced off against Remo's Mega Garchomp, Garchoo, once more. After failing to dodge a hit from Draco Meteor, Charizard Mega Evolved. After a clash between an evenly strong Dragon Claw and Dragon Rush, Charizard grabbed Garchomp and threw it into the air, before hitting it with a Flamethrower. Both Pokémon then clashed using their Dragon Claw attacks, with Charizard emerging victorious. This victory allowed Alain to advance to the finals of the Lumiose Conference.
In Finals Not for the Faint-Hearted!, Charizard was Alain's final Pokémon during their final battle with Ash at the Conference. It battled Pikachu, enduring both his Quick Attack and even a super-effective Thunderbolt. Continuing their battle, Charizard was hit once again by a Thunderbolt, but managed to hit Pikachu with Flamethrower when the Mouse Pokémon was too exhausted to use another Quick Attack. Another Flamethrower was blocked by a shield of dirt created by Pikachu's Iron Tail. Charizard and Pikachu then clashed with Dragon Claw and Iron Tail, but the former was able to overpower the latter, knocking him out. Charizard was recalled when Ash sent out his Goodra.
It was sent out again to face Ash's final Pokémon, Greninja. Charizard first fired off a Flamethrower while both Pokémon headed towards each other. Its attack, however, was dodged, causing it to be hit by Greninja's Cut. Charizard and Greninja then both transformed to their respective more powerful forms, Mega Charizard X and Ash-Greninja. Greninja then started attacking by charging at Charizard while using Double Team. Charizard, however, wiped out its clones with Flamethrower, creating a huge cloud of smoke. Greninja then appeared from the smoke and fired off a Water Shuriken which was countered by Charizard's Dragon Claw. Both Pokémon then engaged in a brawl using Dragon Claw and Aerial Ace, but eventually Charizard managed to outmaneuver Greninja and knock it off its feet with Dragon Claw. Charizard then fired off a Flamethrower, but Greninja used Cut to block the attack. Its next attack, Blast Burn, was also blocked as Greninja created a shockwave by slamming its Water Shuriken on the ground. As another cloud of smoke covered the field, Charizard, unable to see Greninja, was left vulnerable to a powerful Aerial Ace, slamming it onto the ground. It, however, stood up and knocked Greninja back with Dragon Claw. After clashing with Dragon Claw and Cut, Charizard attacked with Thunder Punch, but Greninja used Water Shuriken as a melee weapon to counter the attack and was able to strike Charizard with it. Alain and Ash then had their Pokémon use Blast Burn and Water Shuriken respectively with Greninja's attack changing color and to a massive size. Both Pokémon then fired off their attacks with both scoring a direct hit on their opponent, causing another explosion and leaving the battlefield covered in smoke. Although initially both Pokémon were still standing, only Charizard was able to keep itself from fainting, giving Alain the victory and making him the winner of the Lumiose Conference.
In A Towering Takeover!, Charizard helped to combat the giant roots that were growing over Lumiose City, after Team Flare launched their attack. It was later sent out to free Ash's Pokémon from Lysandre's binds and went to face Lysandre's Pyroar and Shiny Mega Gyarados in battle. After Mega Evolving, Charizard tried attacking Pyroar with Dragon Claw, but it was hit hard by a super effective Stone Edge. During the continuation of the battle, Charizard was able to hit Gyarados with several of its attacks, dealing much damage. It then caught Greninja and Talonflame, after the two were knocked in the air by Gyarados's Stone Edge, but Charizard and the two Pokémon were slammed to the ground by a Dragon Tail. In the following episode, Charizard managed to strike Gyarados with a Dragon Claw, before Pikachu finally finished the Atrocious Pokémon off with a Thunderbolt.
Charizard later helped Serena's Braixen, Steven's Metagross and Professor Sycamore's Garchomp fight against the Megalith Zygarde. It, along with the other Pokémon, was eventually subdued by the creature's roots, but was freed by a combined attack from the Pokémon of all the Kalos Gym Leaders and Diantha. After strategizing, everyone combined their powers to fend off the Megalith Zygarde's roots, allowing Alain and Ash to reach its center and save Chespie, bringing the creature down. After the resurrection of the Megalith Zygarde, who was now controlled by Lysandre, Charizard, Greninja, and Pikachu managed to destroy Lysandre's control device, allowing Squishy and Z2 to destroy the Megalith Zygarde.
In Battling With a Clean Slate!, Charizard helped to save Pikachu from Team Rocket. During the battle, it was seen to be no longer wearing its Charizardite X, which Alain had discarded as revealed in Till We Compete Again!. At the end of the episode, Charizard and its Trainer received medals from Professor Sycamore for their heroic efforts against Team Flare.
In Till We Compete Again!, Charizard was seen by Alain's side in Frost Cavern during Alain's search for Mega Stones.