Mateus is the self-styled Emperor of Decadence. He is unapologetically arrogant, but treats his allies well, earning him quite a few followers. His goals are simple - spreading his influence across the Nightmare Realm, which has somehow put him in conflict with The Prince and his Starbound Court.

He is almost always shrouded by a veil of hallucinogenic smoke. Only those of strong will can withstand its sickly stench and keep their mental clarity in his presence.