Kyogre summons the long-lasting rain that helps restore the Withered Wasteland in Pokémon Pokopia. The event follows Ditto’s discovery of an Onix trapped in a cave that is too hard to break through.
Tangrowth explains that rain could soften the rock, but the area has not received rain for years. Ditto first finds Slowpoke, whose yawns produce a brief rainfall. That short shower awakens Kyogre from its resting place beneath the sea, allowing the legendary Pokémon to summon a much more useful rain.
Kyogre is a fitting choice because it is traditionally associated with oceans and rain. The sequence can be confused with Raikou, which appears later in Bleak Beach and helps drive away clouds. In Pokopia, Kyogre’s role is specifically tied to the rain needed to free Onix.