Satã serves as a recurring antagonist, a powerful warlock obsessed with seizing the protagonist's unique two-hearted soul to conquer the kingdom. He commands supernatural abilities making him immune to conventional physical harm, yet possesses a crippling vulnerability: an overwhelming fear of angels, particularly triggered by an angel's horn, often forcing his retreat from direct angelic confrontation.

Physically, Satã is tall and thin with chalk-white skin and a distinctively pointed nose, typically clad in a skin-tight red suit and black cape. He has a daughter, Zenda (also known as Heckett), whose character draws inspiration from Hekate, the Greek goddess of witchcraft. Initially aligned with her father's goals, Zenda nurtures a secret desire to be good and frequently covertly aids the protagonist in undermining Satã's schemes, creating familial conflict.

Satã allies with other primary antagonists, Duke Duralumin and his subordinate Baron Nylon, secret Satanists who serve him. These alliances drive plots such as attempting to transfer the protagonist's power to Zenda to make her a powerful witch, and multiple efforts to expose or eliminate the protagonist. Despite his powers and alliances, Satã's plans are consistently thwarted, frequently due to angelic intervention and his daughter's betrayals. His role diminishes as the narrative advances, with ultimate villainy shifting to the fascistic Mr. X.

Beyond physical confrontation, Satã embodies a metaphysical evil, fusing Christian and Greek mythological elements that contrast the story's divine forces of angels and God.