Groudon was summoned to ancient Dahara City by Hoopa along with Kyogre, and expressed its rage at this abduction by unleashing its Solar Beam attack on Hoopa, only for Hoopa to redirect it through it's rings to strike Kyogre instead. One hundred years later, Groudon was summoned to Dahara City again in Primal form, where it fell under the dark Hoopa's control along with Palkia, Kyurem, Dialga, Primal Kyogre, and Giratina. It thus launched various attacks against Hoopa's good form, Ash Ketchum and his Pikachu, Rayquaza, Latios, and Latias, while receiving damage such as being briefly frozen by Kyurem.
After Hoopa's dark side was contained by the Prison Bottle, Groudon and the other Legendary Pokémon were freed from its control. They temporarily collapsed but soon revived, and according to the true Hoopa expressed surprise at these developments. Following the destruction of Dahara Tower and a brief appearance by Arceus, Groudon and the others departed for their homes via more conventional means of travel than Hoopa's rings.
|Flamethrower||fire||MS018: Pokémon The Movie - Hoopa and the Clash of Ages|