Agatio is a Mars Adept, who is one of the two main antagonists in Golden Sun: The Lost Age, along with his partner, Karst. The pair follows in the footsteps of the original game's Saturos and Menardi and shares their goal of lighting the four Elemental Lighthouses and restoring Alchemy to the world, but seek vengeance upon Isaac in response to the murder of Saturos and Menardi at his hands at the end of Golden Sun.