Eris is an evil Greek goddess and a villainess in DC comics.
In Greek mythology, Eris is sometimes identified as the daughter of Ares the God of War, or his sister. Other variations on her character name her as the daughter of Kaos, the force of creation. The latter story names her as a personified force, rather than a physical being. It was Eris who caused the Trojan War in ancient times by placing one of her golden apples on Mount Ida during the wedding of Peleus and Thetis. The apple was marked ' to the fairest'; Athena, Aphrodite and Hera all claimed the apple as their own and only the judgement of a mortal, Prince Paris, would settle the argument. After each candidate tried to persuade Paris to choose them, Paris made a decision - that the apple should be given to Aphrodite, the goddess of love. Upon being chosen, Aphrodite fulfilled her end of the bargain and granted Paris the hand of the most beautiful woman in the world; Helen of Sparta. However, Helen was married to Menelaus, the King of Sparta. After Paris entered Menelaus' halls under a peaceful flag and abducted her back to Troy, Menelaus declared war on Troy, and sent his forces, and those of his brother Agamemnon as well as every solider in Greece (a force that filled over 1000 ships) to Troy's gates. The war would last for 10 years, killing thousands and causing discord in the halls of Olympus and amongst the Gods.
In the pre-crisis universe, Eris was the sister of the war god Mars, and the great aunt of Wonder Woman. She joined her brother and her nephews Deimos and Phobos in an attack on the Amazons of Paradise Island. With a spell she cursed Queen Hippolyte into a coma like sleep, one which she could not waken from. Her daughter Diana finally overcome the villians by trapping their armies in a ravine and forcing them to retreat and reverse the spell.
Post crisis and Eris is Ares, daughter and sister to Deimos, Phobos and Harmonia. She meddled in the first cultural exchange between the Amazons of Themyscira and delegates from mans-world. She used her famous golden apples to bring chaos to the conference and sow seeds of distrust between the Amazons and their guests. Eris captured Princess Diana and sent a duplicate to the conference to further the chaos. The reporter lois Lane was almost killed by the mystic Diana before she found and helped free the real Princess from Eris clutches. Wonder Woman, the Amazons and the delegates ended their fighting and let go their feelings of hatred, jealousy and fear, thus deafeating the goddess, who had no power to draw upon. Wonder Woman then destroyed Eris golden apple tree with her lasso of truth, taking the goddess' most powerful weapon. And with this, the goddess disappeared.
Later Eris resurfaced with the sorceress Circe, having saved the witch from her prison in Limbo, to ignite the War of the Gods. Her own agenda was to create so much discord that she would be powerful enough to overthrow her father the War God. As the Holy War turned against them, Circe turned on her ally and began absorbing Eris power to fuel her own magics. The goddess in her weakened state was then dealt her death blow by the Son of Vulcan.
Years later Eris spirit was lifted from Hades by her brother Phobos, and placed in the body of the villian Poison Ivy. Her brother Deimos, who had been slain by Wonder Woman years earlier was placed in the Joker. The three siblings then tried to turn Gotham City into a new base for their father on earth, the Areopagus. With many of the cities citizens under their power, and on the brink of success, it took Wonder Woman, Batman and their allies, along with the War God himself, to end their schemes. Ares wrenched his daughters spirit out of Poison Ivy and she was sent back to Tartarus for her crimes.
The New 52
Writer Brian Azzarello reintroduce the character of Eris in the New 52 relaunched Wonder Woman title. Renamed "Strife", with design from Cliff Chiang, she's still the goddess of Chaos and Discord. She's able to make people confused and generally sow discord, making large group of assailants attack each other in the belief they were the enemy. She's also shown the ability to manipulate her size as well as appearing physically stronger than Wonder Woman.
In this version, she's Wonder Woman half-sister through Zeus. She's sarcastic, venomous, and a drinker, though both Diana and Hermes considers her mentality like that of a spiteful child. According to Diana, Strife has most often been seen in the company of her brother Ares as War and violence often follows Discord.