Fires of a Red-Hot Reunion! (Japanese: 燃えよリザードン！VSカイリュー！ Burn, Charizard! VS Dragonite!) is the 19th episode of Pokémon: BW Adventures in Unova and Beyond.
Heading towards the White Ruins, Ash and co. come across a special Kanto Fair, a fair celebrating the region of Kanto and the various Pokémon that dwell there. Ash is excited to see all these attractions that remind him of home and ends up seeing a cheerful Charmander right on stage. Reminding him of his old friend after telling his stories to them, Ash calls Professor Oak and requests that he sends over Charizard (since he came back from Charific Valley) while he sends Unfezant to his lab. However, once there, Charizard soon meets Iris' Dragonite and a fierce rivalry between them begins with a battle. Will the battle last? Who will win?
The heroes visit a festival dedicated to Kanto. Ash already recognizes some Pokémon, like Squirtle, Charmander and Bulbasaur. Ash decides to explore this festival, with his friends following him. Passing by a trader wanting to sell Magikarp, the heroes soon see Prof. Oak on the screen, who introduces Squirtle, Bulbasaur and Charmander, the Kanto Starter Pokémon. N asks which Pokémon Ash chose. Iris replies he chose Pikachu, so Ash explains to N Pikachu was the only Pokémon left, for he overslept on that day. Cilan calls this fate. Prof. Oak logs out, while the announcer decides to show some Kanto region Pokémon. N admits this is his first time seeing such Pokémon.
The announcer shows a Charmander, who walks to the stage and turns around, showing its happiness. Iris admits Charmander's cute, but free spirited. Charmander spins around and uses Ember, but becomes dizzy and starts wrecking the stage. Later, Nurse Joy healed Charmander, while the announcer replies Charmander got excited in front of an audience. The heroes ask how is Charmander and Nurse Joy replies it'll be fine soon. Later, Ash admits he was thinking when he caught his own Charmander. Ash still remembers Charmander's original trainer had abandoned it (claiming it was too weak) and he, Brock and Misty went to rescue Charmander and took it to the Pokémon Center before its flame on the tail went out. N is certain that trainer did not want to return to pick Charmander up. The next thing, Charmander, after being healed and burned Team Rocket, was visited by Damien, his original trainer. Damien tried to catch Charmander back, but was hit back by his own Poké Ball. Ash welcomed Charmander into his team.
Charmander fought well against Primeape (who took Ash's hat) and Koga's Golbat, winning Ash the Soul Badge. Also, when they were stuck in snow, Ash's Charmander, along with Bulbasaur, Pidgeotto, Squirtle and Pikachu, shared their warmth with their trainer. Eventually, Charmeleon evolved, but also started disobeying Ash. Cilan heard when a Pokémon evolves, its personality changes as well. Ash still battled with Charmeleon and when he was trapped by an Aerodactyl, who taunted Charmeleon, Charmeleon evolved into a Charizard. They still went to the top, for Charizard battled Blaine's Magmar and won. Unfortunately, at the Indigo Plateau, Charizard wouldn't listen to attack Sparky and costed Ash the victory. Iris sees Charizard was more of a pain, but Cilan sees Charizard reminds him of her Excadrill and Dragonite.
Everything turned around when Charizard fought against Tad's Poliwrath. Poliwrath defeated Charizard and reduced its flame. During that night, Ash warmed up Charizard and told they will be getting stronger together. The next day, Charizard started obeying Ash and used Seismic Toss on Poliwrath, winning the battle. Cilan is surprised Ash does not travel with such a powerful Pokémon. Ash admits Charizard is training at the Charicific Valley. After becoming so powerful, it won every battle, but encountered many Charizard and was defeated by all of them. Ash left Charizard there, knowing it would get much stronger by training there. Eventually, Ash used Charizard to battle Clair's Dragonair and won the Rising Badge, the battle against Gary and his Blastoise, even Noland's Articuno for the Knowledge Symbol.
Ash is certain Charizard is still in training. The announcer of the festival comes and apologizes for the trouble. Charmander is okay, so Ash pats Charmander, asking to be careful. Iris and Cilan would like to meet Charizard. Ash admits he would like to see it as well and decides to bring it back. Ash contacts Prof. Oak and decides to trade Unfezant back. Oak replies Charizard has just arrived from Charicific Valley. Oak is certain Staraptor and Swellow would be glad with another flying-type Pokémon like Unfezant. Ash comes outside and sends Charizard. Charizard roars away, making Cilan, Iris and N thrilled to meet it. Charizard burns Ash with Flamethrower, as a way to greet him. N already senses Charizard has a deep history with Ash, proving how great friends they both are.
Ash and Iris send their Pokémon to meet Charizard. However, Charizard has his eyes on Dragonite, as they both have just developed a rivalry. Cilan and N see these two are drawn to each other. Ash advises to Iris they can have a battle to test their strength. Iris accepts and both take positions. Dragonite starts with Flamethrower, but is countered by the same move from Charizard. Charizard and Dragonite fly up. Dragonite uses Thunder Punch, but misses Charizard, who hits it back with Wing Attack. Charizard uses Slash against Dragonite's Dragon Rush. Both fall down, but are able to continue. Charizard flies up and hits Dragonite with Dragon Tail. Both descend down and N stops the battle, seeing both sides are very powerful. Charizard and Dragonite agree, fascinating Cilan they made new friendships.
Iris wonders why didn't Dragon Rush do more damage on Charizard, being a dragon-type Pokémon. Ash, Cilan, Pikachu, Charizard and Dragonite are surprised, so Ash tells Charizard is not a dragon-type Pokémon, but a flying-type. Iris is shocked, for she was certain to catch and raise a Charizard, making Axew laugh at her. Ash asks Charizard if it wants to come back for this journey. The others want too, as does Charizard, to come back and accepts the offer
- All the characters and backgrounds in the flashbacks have had animation redesigns to fit the BW series. These scenes were also redubbed by the current TPCi cast rather recycling the 4Kids voices.
- Instead of Rachel Lillis returning, Michelle Knotz (who voiced Misty in Mastermind of Mirage Pokémon) voices her in the flashbacks of this episode.
- Although Team Rocket appears in a flashback, they are barely visible as in the scene they appear that they are being burned by Charmander's Flamethrower, leaving only their weak silhouette visible.
- This is Sarah Natochenny's first time portraying Ash in the Original Series via flashbacks.
- This is the first time Misty and Tracey appear in the BW saga.
- Who's that Pokémon?: Charmander.
- Though Liza did not have a speaking role, Lisa Ortiz provided the voice of the unknown female Charmander trainer.
When it is shown Koga battling Ash, Charmander defeats Golbat with Flamethrower, when in the original episode, it wins with Fire Spin.