The Supreme Master of the Underworld (AKA Octomus) is the main antagonist of Mystic Force and the true leader of the Forces of Darkness and his minions revere him so much that he has only ever been referred to by his title. He contacts his minions via the white pool at the center of their lair, which turns red to signal his presence. His true form was revealed to be an immense Cthulhu-like demon with a skull-like face, many tentacles and dragon heads on the end of each tentacle, but usually only his right eye can be seen. His other eye is embedded in Koragg's shield, and one of his fangs was used to make Morticon's sword (which was taken by Koragg when Morticon was destroyed and forged into a new Knight Saber) and quite possibly some of his claws were given to Necrolai, her "Claws of the Master".