Shadow Pokémon are the core mechanic of Pokémon Colosseum. These are Pokémon whose hearts have been artificially closed by Team Cipher, making them aggressive and unable to level up normally. They have a unique 'Shadow' type move (e.g., Shadow Rush) and cannot learn new moves or evolve until purified.
Snagging: To obtain a Shadow Pokémon, you must use your Snag Machine to 'Snag' it from another trainer during battle. This is similar to catching a wild Pokémon, but you're stealing it from an opponent. You'll need to weaken the Shadow Pokémon first, then use a Poké Ball, Great Ball, or Ultra Ball. Remember, you can only snag one of each unique Shadow Pokémon.
Purification: Once snagged, a Shadow Pokémon's 'Heart Gauge' will be visible. This gauge decreases as you perform various actions:
- Walking around with the Shadow Pokémon in your party.
- Battling with the Shadow Pokémon.
- Using the 'Call' command in battle (if the Pokémon is in Hyper Mode).
- Massaging the Shadow Pokémon at Agate Village.
- Using a Cologne Case at the Relic Forest.
When the Heart Gauge is completely empty, take the Pokémon to the Celebi Shrine in Agate Village to complete the purification process. Purified Pokémon gain access to their full move pool, can level up normally, and are no longer aggressive.