Ares is the god of war and the father of Clarisse, Percy’s primary adversary at Camp Half-Blood.  He is arrogant and strong, and possesses a wicked temper. He is also highly skilled in the art of deception. He is depicted as a large and muscular biker who rides a motorcycle with a seat made of human skin. True to his title, Ares can alter people’s moods to make them angry enough to start a fight. He has two major functions in the novel. Firstly, he generates much of the novel’s plot by working with Kronos and Luke to frame Percy for stealing the master bolt, in an effort to start another war by pitting Zeus, Poseidon, and Hades against each other. He explains to Percy, “See, you’ve got to die in the Underworld. Then Old Seaweed will be mad at Hades for killing you. Corpse Breath will have Zeus’s master bolt, so Zeus’ll be mad at him. And Hades is still looking for [the Helm of Darkness].” With the three most powerful gods at one another’s throats, World War III would become not a hypothetical but a reality.

Ares is also significant because he inadvertently highlights Percy’s heroic transformation. Percy has two run-ins with Ares. The first time they meet, Ares tricks Percy, Annabeth, and Grover into doing his bidding, which almost gets them killed. The trio’s initial interaction with Ares occurs towards the beginning of the novel, when Percy is still growing into his hero status. Percy and Ares meet again towards the end of the novel when Percy challenges him to a fight on the Santa Monica beach. Not only does Percy display an impressive amount of courage by challenging the god of war to a fight, he also manages to best Ares by harnessing the Santa Monica Bay. Percy’s charisma, his reflexes, and his successful manipulation of the sea confirm that he has matured into a true hero.