Ator and his brother Trogar are separated as children by the evil witch Phaedra who gets banned for this. She is sentenced by three other witches who seem to represent a magical jury. Phaedra is banned and loses her magical powers.
18 years later she returns, accompanied by an undefeatable warrior who is wearing a silver skeleton skull mask. The fighter kills the king and his guards and Phaedra can take over the power. Princess Janna is the only one to escape but is soon caught by the masked warrior. Janna shall be sacrificed in a ceremony but is saved by Ator who escapes a trap set for him. He fights the masked warrior and kills him, but realizes soon, that he is not dead because of Phaedras magical powers.
To defeat her, they have to get an artifact on the mystic island of Stygian. After surviving some traps (rolling stones like in "Raider of the Lost Ark") and fighting the guards, they take the golden chest and hardly escape the island that is sinking. Ator is now able to kill the masked warrior who is his lost brother Trogar.
In the end Ator unmasks Phaedra who has shape-shifting powers and has hidden herself in another kingdom as the lover of the king. By magic they are suddenly transferred to another place. Phaedra has captured princess Janna who hangs from a cliff. Phaedra steps on her hands. Ator has to fight his way through some guards again and meets Phaedra who seems invincible to his sword. After some tries he takes a torch and burns her, also throwing her from a cliff. Suddenly Ator sees a bound Janna nearby. He helps her. Janna embraces Ator, looking into the camera in a strange way.
In the last scene Phaedra is not dead but captured again by the other witches. They discuss who really won the fight, leaving it open if Janna is possessed or just shocked. They come to the conclusion that love is the winner.