Kratos

Kratos is the main character of the God Of War series and although technically the protagonist of the series is a violent man who has many of the traits of a villain, he is driven by a desire for vengeance and will stop at nothing to tear Olympus apart and slay the gods themselves.

Throughout the games the player controls Kratos and aids him in his voyage, which takes him across many epic worlds based on Greek mythology - Kratos is portrayed from the very start of the series as a merciless warrior who kills his enemies without remorse and without pity, his hunger for revenge makes the mass slaughter of others justified in his own eyes and as such he is as much an antagonist as a hero: though in fairness Kratos inhabits a world that is very dark and morally ambitigious - however even in this setting Kratos stands out as a man who is prepared to destroy the world if necessary in order to end the rule of the Olympians.