Scion of darkness ruling and protecting those who live in the underworld, in opposition to Lahabrea, Abyssal Celebrant and scion of light. In the course of his rule, he submitted to avarice, and the darkness took his heart, transforming him until he was both evil and corrupt. Then in his cowardice did he bind a Goddess of the Demesne of Ice, and using her as a living shield, he challenged the gods. Defeated before their might, he fell screaming into the depths of hell, there to be imprisoned for eternity.

Mateus is also encountered during the main storyline. This evil being appears to have entrapped an ice goddess, so it uses a variety of ice magicks. Mateus is more useful when facing c reatures that are weak against ice magick. It also has a healing spell that can help keep itself and the summoner alive when facing a group of enemies.