The god Hephaestus is working to forge a mechanical creature for Ares – the Annihilator, which proves capable of threatening even Ares himself. Ares then sells the mechanism gratis to the Northern side of two warring paramilitary factions. In the city, Wonder Woman interrupts bank robbers during her day off and makes her displeasure known. J'onn interrupts to send her to Kaznia where two warring factions are ripping the country apart. He sends her to get two fellow Leaguers – Hawk and Dove, brothers who are in the middle of a bar fight. An irritated Wonder Woman interrupts to send them on the mission.
The Leaguers arrive in Kaznia as the Annihilator begins its assault. The pacifistic Dove breaks up the fighting while Wonder Woman and the aggressive Hawk take on the Annihilator directly. The mechanism is proof against their powers and Wonder Woman spots a symbol on it identifying it as Hephaestus' creation. Ares is unhappy that the Northern Kaznians aren't using the Annihilator to full effect and deposes the leader, taking his place.
Wonder Woman confronts Hephaestus who admits he left a small weakness in his creation but refuses to identify what it is. Dove and Hawk try to bring the warring factions together but Ares captures Dove. Hawk is interrupted in his mission when the Annihilator and the Northern Kaznians arrive with Dove strapped to the Annihilator's chest. Hawk frees his brother while Ares leads the Northern forces. The League is unable to stop either the Annihilator or the two sides and Wonder Woman realizes the Annihilator is fueled by rage. Dove confronts the Annihilator, and it shuts down when it loses its energy-source. Ares leaves the field as the fighting dies down, but warns that he'll be back.
Hawk & Dove
Hawk & Dove, in one form or another, are heroes in long-standing at DC. First created at DC in 1968 (Showcase #75) by the ubiquitious Steve Ditko (who appears to be this season's Jack Kirby as far as writer/artists influencing show content), they were brothers Hank and Don Hall - Hank was the militant and Don the pacifist. When they were given the power to save their father, a judge, by a mysterious godlike "Voice," they both manifested as their respective philosophies. They eventually joined the Teen Titans (#25), and later became members of Teen Titans West. They got a perfectly decent "Whatever happened to them?" story in Brave & The Bold #181 (which showed them as adults 12 years after the start of their careers), but it's been pretty much nixed as a Hypertime alternate reality. Don then went on to "die" in Crisis, Hank tended to go berserk without the restraining influence of his sibling, and he later got a new female Dove, Dawn Grainger. It later turned out they were embodiments of the principles of the Lords of Order (Dove) and Chaos (Hawk), created by a lord of Chaos and a Lady of Order who had fallen in love. Hawk later became the evil Monarch of the future, coming back into the past to kill Dove. Hawk/Monarch later became Extant and was destroyed by the JSA, and Dove was secretly resurrected by Mordru, who hopes to use Dove's and Hawk's child, a balance of Order and Chaos, for his own evil purposes. And so it goes... This is their first appearance in the WB animated universe.
Ares (sometimes Mars) has been part of the DC comics since Wonder Woman's introduction (in All-Star Comics vol. 1 #8 - Winter 1941-42). It was Ares that taunted Aphrodite by claiming that he "ruled" the world since all the nations were at war. It was Aphrodite that appealed to Queen Hippolyte to send an Amazon into Man's World to bring peace. Ares, enraged, opposed Wonder Woman on many occasions and used minions such as the Duke of Deception, Phobos, and Deimos. He's also part of the post-Crisis mythos and recently with the Greek Gods "going public," Ares has decided to do some PR work and is slowly working to subvert Wonder Woman and those close to her by taking on a more appealing public appearance. This is his first appearance in the WB animated universe.