Warkiller
Warkiller is a fictional character owned by DC Comics and used in the Wonder Woman comic books. He is based on Achilles of Greek mythology. This version of the Achilles character was created by writer Gail Simone and artist Aaron Lopresti.
Fictional background
Origin
The Greek god Zeus, for his own reasons, kills the Hawaiian god Kāne Milohai and tears out his heart. He then takes the heart to the island of Thalarion, where he calls forth an audience of his newly created subjects: the Gargareans, reanimated and rejuvinated corpses of the long fallen Argonauts of Greek myth. Zeus then tells them that the time has come and magically causes a fire to burn brightly. Within the fire a skeletal being reaches out and takes Kāne Milohai's heart from Zeus' hand. The heart's substance then engulfs the fiery skeleton and forms a body. Zeus then presents the new being, Achilles, and dubs him the codename Warkiller. Zeus informs the Gargareans that Achilles is to be their new leader and figurative son to the Gargarean Jason. To serve as Achilles' personal transport, Zeus also created a massive and powerful elephant named Mysia who has two trunks, two mouths, three glowing eyes, an impenetrable hide, and the ability to walk on air.
As part of the Gargarean's goal to slaughter dictators and dismember warmongers as a way of bringing harmony to the world, Achilles and his people attack several countries and disrupt a United Nations assembly. Shortly after Wonder Woman is informed of their existence she confronts them during an attack in Russia. Wonder Woman informs Achilles during battle that they are being used by outside forces and demonstrates their naivete by safely detonating a warhead they mistakenly launched in the sky above them. Achilles takes this example to heart.
Unknown to Achilles, one of the Gargareans (Euphemus, the son of the sea god Poseidon) allied himself with the war god Ares. At Ares' command Euphemus caused a swarm of deadly sea creatures to attack both Thalarion and Themyscira. The Gargareans joined forces with the Amazons in defending their nations. Initially Achilles wished to kill Euphemus for his treachery, but is convinced by Jason to exile him instead.
New leadership
Shortly thereafter, Zeus decrees that the Gargareans and the Amazons are to become one people. To head the new nation, Queen Hippolyta is to step down from her royal station and be replaced by Achilles. Establishing Themyscira as a new home, Achilles then naively takes the rogue Amazon Alkyone as his bride. He does this in the hopes that the Amazons and Gargareans will see the marriage as an example of bridging the gaps between the two peoples. Both he and Alkyone agree that the marriage would be figurative only, and that they both would find [...] conquests outside of the marriage. As a wedding gift, Alkyone presents Achilles with a shabby male version of the Wonder Woman costume, which she made with her own hands. The marriage ultimately works against Achilles though as Alkyone manipulates her new husband and station for her own ends. She convinces Achilles to emprison Hippolyta and Diana.
When he discovers that Alkyone means to kill Diana, he turns on his wife and her cohorts in battle. Alkyone uses the goddess Athena's virgin spear to pierce Achilles' heart, thinking that it's godly magic would penetrate his invulnerable skin and kill him. Although the spear does go through his body, Achilles tells Alkyone that his heart is that of a god and will not be so easy to destroy. Regaining their freedom, Hippolyta shoots Alkyone with arrows and Wonder Woman throws the Hecatonchire titan Cottus on top of Alkyone, crushing her already wounded body and seemingly destroying her. Achilles then apologizes to the Amazons for his actions, and a new unseen governmental structure takes place on Themyscira.
Achilles returns to Thalerion but is convinced by Diana to also purchase a home of his own in the United States of America. Meeting with a real estate agent named Patrick Cleese, Achilles purchases what seems to be the Playboy Mansion in Los Angeles, California. Achilles is fascinated by Patrick's given name as it sounds very much like that of his former lover Patroclus. Believing Diana had purposefully set Achilles up on a potential "date" with Patrick, he wishes a blessing on the Amazon for her kindness.
Abilities
Achilles possesses physical strength enough to easily break apart marble or stone with his bare hands; the ability to anticipate an opponent's attack and dodge their blows at a near super human speed; has a high invulnerability level; possesses an accelerated healing system; and can magically change his clothing according to whatever he wills. Achilles also possesses the goddess Athena's Virgin Spear, a magical weapon that can pierce any substance it comes into contact with.
As Achilles was able to fight effectively against an Amazon possessing 3,000 years battle experience, it can be assumed he is a very capable hand-to-hand fighter.