They debut in Chapter 229.
Utilizing their Chimecho and likely their own powers, the pair manage to psychically travel from Mt. Pyre to Route 123, where they tell Winona and Sapphire of the Jewels and inform them that their true enemy is the person controlling Kyogre and Groudon, deep in the Seafloor Cavern. They also tell Winona that Tate and Liza are secretly guardians of Mt. Pyre, and reveal that the director of Hoenn's Pokémon Association is aware of this fact.
When the director arrives, they admit to wanting to find Tate and Liza. They accept his invitation to stay on the Pokémon Association's airship.
Chimecho help the two travel from Mt. Pyre to Route 123.