Zeus is the main antagonist of the Greek Era of the God of War series. Serving as the God of Lightning, the Sky, and Law and Order, and the King of both Olympus and the Gods of Olympus, he started out as one of Kratos' allies so he could kill Ares, but after Kratos opened Pandora's Box, Zeus got scared of Kratos and decided to kill him, before Kratos could kill him. He became the main antagonist following the events of the original God of War storyline (Which were God of War II, and God of War III). Specifically, he makes a brief appearance in God of War, then appeared in God of War: Ghost of Sparta as the Grave Digger, then was the main antagonist of God of War II and God of War III. He is the king of the Olympians and was originally a fair god by Olympian standards but grew to become one of Kratos' most powerful and merciless opponents as the series progressed. As revealed during the ending of God of War II, it was revealed that he is also Kratos' father. Zeus is also Kratos' nemesis (since his betrayal). Because of his recurring appearances and being Kratos' nemesis, Zeus is the Big Bad of the entire Greek mythology era of the God of War series.