Both Manaphy and Phione are available for capture in This includes Manaphy, Phione, and many other Sinnoh favorites.
Manaphy and Phione are two mythical Pokémon that debuted in Pokémon Diamond and Pearl. It was only available as a special trade event where those who owned copies of Pokémon Ranger were able to get a special egg. After walking a few thousand steps, the egg would eventually hatch into Manaphy. The thing that makes Manaphy so special is that it's one of the few Pokémon that can breed. Although, Phione will end up as the result of that breeding. In Pokémon Legends: Arceus, both can be found in the ocean's depths.
After clearing the main story, the player will be able to take on additional quests as the world continues to open up. Head to the blackboard inside of Professor Laventon's office and choose Request 66: The Sea's Legend. For this quest, trainers will need Mantyke, Qwilfish, and Buizel, all Pokémon that can be found within the Cobalt Coastlands. Make sure it's evening time and go to Sea's Gate. A special message will appear if the trainer es through the gate with these Pokémon during nightfall. Continue deeper into the ocean towards the rocks to find a cave entrance.
Catching Manaphy and Phione in Pokémon Legends: Arceus
Upon entering the cave, trainers will find Manaphy along with three Phione. The Manaphy will be level 50, while each Phione will be level 33. To avoid killing them in battle, make sure to use Agile Style on the Pokémon's moves. This will lower the attack damage for that move, making it weaker and preventing the Pokémon from fainting. Additionally, it's recommended to capture every Pokémon in the room since it helps complete the Pokédex.
Make sure to capture them all since this is the only time and place Manaphy and Phione are both available. Collecting them all will complete their research task and help build up the player's Star Rank in Pokémon Legends: Arceus. It's currently unknown how Pokémon Home will work with Pokémon Legends: Arceus, but Manaphy is incredibly rare and can be useful for future trading. In the Sinnoh region, it's regarded as the Prince of the Sea. It uses its powers to protect the Pokémon of the ocean, and they work together to preserve it.
Pokémon Legends: Arceus is available now on Nintendo Switch.