In God of War II, Kratos discovers that Zeus is his father. This revelation becomes a major reason for Kratos's rebellion against Olympus.
At the beginning of the game, Zeus betrays Kratos and strips him of much of his power. Kratos survives through the intervention of Gaia and the Titans, then seeks revenge against Zeus and the other Olympian gods. The game expands the first title's personal conflict into a larger war between the Titans and Olympus.
The relationship is based loosely on Greek mythology, where Zeus is also the father of many divine and heroic figures. However, the God of War series changes the circumstances, personalities, and chronology of the myths. Ares remains important because he was Kratos's former master and the final enemy of the first game, but he is not Kratos's father.