The true identity of Rider is Medusa, the Gorgon of Greek mythology. Instead of a Heroic Spirit, it is an existence closer to a Divine Spirit, but its actions make it closer to an "anti-hero", almost a monster. Together with his older sisters, Esteno and Euríale, they make up the three Gorgon Sisters who inhabited the island without form. She was known as the "woman who dominates", who became an anti-hero due to the dark thoughts of human beings. Unlike someone like Hassan-i-Sabbah who was a hero who really existed, it is said that she is one of the legends born of the union of beliefs
