When you reach the end of the main story quest in Pokémon Legends: Arceus, it’ll be time for you to reach out to the Clan leaders and learn about the precious treasure they have. Adaman will be waiting for you on the shores of Lake Valor, and if you speak with him, he’s willing to show you that treasure if you can defeat him in a battle. This guide will cover how to complete The Diamond Clan’s Treasure request in Pokémon Legends: Arceus.
You can find Adaman to the north of the Diamond Clan camp in the Crimson Mirelands. When you approach him, he’ll want to share a precious treasure that he discovered not too long ago that is sacred to his clan. However, he will not share or give you the treasure until you’ve defeated him in a battle. Once you accept, you’ll have to fight him.
Adaman will be us three Pokémon at the same time. He will have Leafon, Umbreon, and Vaporeon. The Leafeon will be at level 64, whereas the Umbreon and Vaporeon are at level 32. You’ll have to battle all three of them, and of the three, we recommend focusing on the Leafeon first.
Leafeon is a Grass-type Pokémon, making it weak to Fire, Ice, Poison, Flying, and Bug-type moves. Of those choices, we recommend focusing on using Fire or Ice-type attacks to quell Leafeon during the battle. You’ll also want to primarily focus on Leafeon because, while the other two do have attacks and are annoying, they’re significantly weaker than Leafeon.
After beating Leafeon, you can move on to Vaporeon and Umbreon in whatever order you’d like. Vaporeon is a Water-type Pokémon making it weak to Electric and Grass-type moves, whereas Umbreon is a Dark-type and is weak to Fighting, Bug, and Fairy-type moves.
Once you’ve completed the battle and defeated Adaman’s Pokémon, he will offer an item you can use to change Dialga’s forme, the Adamant Crystal.
