You may need to import the battery save that matches the game running in VBA-M while the GBA BIOS is active for Dolphin to establish the link properly.
Although unstable and barely functional for Pokémon Colosseum, the recommended releases of VBA-M to use the GCN-GBA emulated hook-up are the WXVBAM versions. In stable releases of VBA-M, the GCN-GBA connectivity does not work properly, causing severe slow-downs to the point where both games timeout before an emulated connection can be established. Those that pre-ordered the game received the Pokémon Colosseum Bonus Disc.
Pokémon Ruby, Sapphire, Emerald, FireRed, and LeafGreen can connect to this game through trading and Battle Mode. The game also features several battle modes for single-player and multiplayer gameplay. Unlike previous titles, the game does not feature random encounters with Pokémon, but the player can steal ('Snag') the Pokémon of other Pokémon Trainers. Pokémon Colosseum ( ポケモンコロシアム, Pokémon Koroshiamu) is a role-playing video game developed by Genius Sonority and published by Nintendo as part of the Pokémon series, released exclusively for the Nintendo GameCube.