Retrieve the Manaphy Egg
Flip on the "Power" switch of your Nintendo DS with the "Pokemon Ranger" game placed inside the Nintendo DS's game slot. Go to the Oblivia Region, where there will be a Manaphy egg. Pokemon Pinchers, characters in the game that are known to capture and take the Pokemon away from their habitats, will steal the Manaphy Egg. The Pokemon Pinchers will try to run away with the Manaphy egg by swimming underwater, so you will also have to follow them underwater. Chase after the Pokemon Pinchers to retrieve the Manaphy egg.
Send the Manaphy Egg to other Pokemon Games
Connect your Nintendo DS to the other Pokemon games that are available on the DS, such as "Pokemon Diamond" version, "Pokemon Pearl" version, "Pokemon Platinum" version, "Pokemon HeartGold" version and "Pokemon SoulSilver" version to transfer the Manaphy egg.
Hatch the Manaphy Egg
Once the Manaphy egg is transferred to another Nintendo DS Pokemon video game, wait a moment for the egg to hatch. You will now have a Manaphy, a water-type legendary Pokemon.
Retrieve a Bonus Phione Pokemon
Bring Manaphy, the water-type legendary Pokemon and Ditto, the normal-type Pokemon to the Pokemon Day Care center. Wait a moment for a Phione Pokemon egg to appear and hatch into Phione, which is also a water-type Pokemon. Once you capture Phione, you can now use Phione for gameplay in the other "Pokemon" DS video games.