From Bulbapedia, the community-driven Pokémon encyclopedia.
Eldes (Japanese: エルデス Eldes) is one of the five Cipher Admins of Pokémon XD. Eldes is seen early on in the game, but the protagonist doesn't fight Eldes until near the end of the main storyline.
As well as being a Cipher Admin, Eldes serves as one of Greevil's two bodyguards, the other being Ardos. At the end of the game, it is revealed that Eldes is one of Greevil's two sons. Eldes eventually stops Greevil and Ardos from fleeing the base and blowing it up with Michael still on it.
The protagonist first battles against him in Citadark Isle, where he uses a total of four Shadow Pokémon. After Greevil has been defeated, the player can challenge Eldes on the last round of the Orre Colosseum.
Among Eldes' Shadow Pokémon are Marowak, Lapras, Manectric, and Salamence.
Pokémon
At Citadark Isle
At Orre Colosseum