Maxie sent Camerupt out in his headquarters to breathe fire, to create more land, which was Maxie's goal. While walking from the Hoenn TV station towards his car, Archie sensed Maxie was nearby and sent Walrein to the battle. Maxie sent his Camerupt, who started attacking Walrein. Walrein tried to freeze Camerupt with its tusks, but Maxie reminded him Camerupt's Magma Armor prevented it from becoming frozen. Instead, Camerupt launched Eruption, which Walrein survived, since its Thick Fat ability reduced the damage from such attacks. Since Maxie proposed Archie to work together to go to Seafloor Cavern, Archie accepted the request and both leaders called their Pokémon back and ended the battle.
Maxie and Archie joined together to battle Ruby and Sapphire. Maxie sent Camerupt and Archie his Walrein, the latter getting hit by Ruby's Swampert, Mumu, and Sapphire's Blaziken, Chic. Just as Mumu attacked with Muddy Water, Camerupt launched Eruption and Walrein used Sheer Cold, which hit Sapphire and Ruby's Pokémon. Fortunately, Ruby's Castform defeated Maxie and Archie with Hail and Weather Ball.
Walrein and Camerupt were sent to battle Ruby's Mumu and Sapphire's Chic. Chic used Sky Uppercut and Swampert fired Muddy Water, which defeated Camerupt and Walrein. However, Maxie sent more Houndoom and Archie sent more Walrein to battle Ruby and Sapphire, while the bosses tried to make their escape in their aircar.
Just as Maxie and Archie came to Hoenn with the Red and Blue Orbs they stole, Red and Green pursued them. Red and Green sent Venusaur, Saur, and Blastoise, Blasty, against Maxie's Camerupt and Archie's Sharpedo. Archie and Maxie Mega Evolved their Pokémon, but so did Red and Green. In the hard battle, Blasty and Saur managed to defeat Mega Camerupt and Mega Sharpedo. However, Maxie had Primal Groudon encase Red and Green under some rocks, preventing them from interfering the bosses' mission.
Since their original trainers died, Amber took Archie's Sharpedo and Blaise took Maxie's Camerupt. In addition, both of them took their bosses' Key Stones, allowing them to Mega Evolve Camerupt and Sharpedo. Both Blaise and Amber used these Pokémon to launch an attack to shatter the meteorite that threatened to collide with the planet.
|Eruption||Walrein and Camerupt|
|Overheat||The Beginning of the End with Kyogre & Groudon X|
|+ indicates this Pokémon used this move recently.*|
- indicates this Pokémon normally can't use this move.