Why Did Kratos Kill Zeus?

Kratos killed Zeus for revenge. Zeus betrayed him at Rhodes, tricked him out of his godly power and ran him through with the Blade of Olympus, because he feared his son would one day kill him. Kratos came back from the dead to repay him, and by the end of God of War III the feud had wrecked Olympus and all of Greece. (God of War II; God of War III)

The betrayal at Rhodes#

At the start of God of War II, Kratos sits on Olympus as the new God of War but uses the throne to lead Sparta's army against the cities of Greece. The other gods are furious. When he joins his men at the siege of Rhodes, an eagle swoops down and drains part of his power into the giant statue of the city, which comes to life. (God of War II)

Zeus then offers him the Blade of Olympus to fight it. Kratos pours the rest of his godhood into the sword without asking why, and is left mortal. Once the statue falls, the eagle lands and becomes Zeus. It had all been a trap. Zeus feared Kratos would kill him the way he had killed Ares. He told Kratos to submit, and when Kratos refused, Zeus killed him with the blade. (God of War II)

Athena's secret#

The Titan Gaia pulled Kratos back from the Underworld, because the Titans hated Zeus too. With their help he reached the Sisters of Fate, used their power to go back to the moment of his death and took the blade from Zeus. The God of War II story covers the whole quest. (God of War II)

Beaten, Zeus tried to slip away. Kratos thrust at him, and Athena threw herself in front of the blade. Dying, she told him that Zeus was his father. Zeus had overthrown his own father, Cronos, and feared his son would do the same to him. That was why he had turned on Kratos. (God of War II)

Kratos said he had no father. Athena warned him that all of Olympus would stand with Zeus, and Kratos answered that if Olympus denied him his vengeance, Olympus would die. (God of War II)

The older grudges#

Rhodes wasn't the only score. Ghost of Sparta shows that Ares and Athena took Kratos's little brother Deimos from Sparta because of a prophecy that a marked warrior would bring down Olympus. They took the wrong brother. Kratos was the one the prophecy meant. (God of War: Ghost of Sparta)

The series keeps returning to the same idea, which the site covers as the cycle of patricide. By trying to stop his son from killing him, Zeus gave his son every reason to do it. (God of War II; God of War: Ghost of Sparta)

How Kratos killed Zeus#

God of War III picks up straight away, with Kratos riding Gaia up Mount Olympus. He kills god after god on the way, and each death brings ruin: the seas rise, the sun goes dark, plague spreads. (God of War III)

In the final fight, Zeus's spirit drains Kratos almost to death. Inside his own mind, guided by the spirit of Pandora, Kratos faces his guilt over the deaths of his wife and daughter and forgives himself. A power rises out of him. He wakes, pins Zeus to the ground and beats him to death. (God of War III)

Athena, back as a spirit, later explains what that power was. It was Hope, which had been inside Kratos since he first opened Pandora's Box. Kratos then drives the Blade of Olympus through himself to give that Hope to what's left of humanity, rather than hand it to Athena. The God of War III ending explained covers that scene. (God of War III)

Was killing Zeus worth it?#

The game doesn't think so, and neither does Kratos in the end. Greece was left drowned, sick and dark, and Kratos tried to die on a cliff. (God of War III)

Years later, in the Valhalla epilogue to Ragnarök, the god Tyr pushes him to own those memories, Pandora, the Box and what he did after Zeus died. Our reading is that this is the series' final word on it: Zeus earned his fate, but the revenge cost Kratos nearly everything, and the one thing worth keeping from it was the Hope he gave away. (God of War Ragnarök: Valhalla)