Here are the details about the D/P transfer system:
- You can transfer 6 Pokémon from each of your games to D/P per day.
- You have to catch the Pokémon you transfered in a Park.
- The Park Balls have 100% capture rate.
- The rarer your Pokémon, the harder it will be to find.
- You cannot transfer your Pokémon back to your GBA games.That means tha by the time you transfered them to your D/P they cannot go back.