Scar (Green Lantern)

Scar was a female member of the ancient and powerful Guardians of the Universe, a group from an immortal race that is nearly as old as the universe itself, and the founders of the Green Lantern Corps. During the battle with the Anti-Monitor in the Sinestro Corps. invasion of Earth, the Guardian that would become Scar was badly burned by contact with the villain, and apparently killed. Despite not knowing it herself, she was instantly resurrected via the influence of Nekron, who overtime used her as a sleeper agent within the Corps. to weaken it from within before the Blackest Night occurred.

Origins
Billions of years ago, the Maltusian race reached a peak in evolution via bonding with symiotic creatures that gratend them immortality and cosmic powers on par with that of Gods. United without need of want or need, the Maltusians dedicated themselves to science and understanding. One of their number, Krona, decided that he should see the beginning of creation, and the origins of his race, an act condemned by a legend amongst his kind that doing so would unleash a great evil into the universe. Krona went ahead with his plan, and accidentally created the Anti-Matter Universe, and via a leaking of Entropic-energy into the beginning of the Universe, caused creation to be born a billion ears old, wiping out a billion years of potential life.

A group of the Maltusian race felt guilty about this act. They took the mantle of Guardians of the Universe, and absonded emotions in favour of cold logic. Upon finding that Krona did not plan on giving up emotions, they pursued him, and punished him for his part in causing such calamity in the universe.

The male Guardians would travel to Oa, the centre of the Universe, and become the Oan race, what is colloquially named the Guardians of the Universe, and founders of the prestigious Green Lantern Corps. The female members would consider the abandoning of emotions as heresy, and depart for the planet Zamaron.

In the modern day, the Guardians but for Ganthet would be killed by a Parallax infected Hal Jordan, and later resurrected into male and female children Oans by Kyle Rayner. Following the resurrection of the Green Lantern Corps., the Guardians would become concerned about certain signs regarding the prophecy of the Blackest Night, but the majority of them would disregard the signs as nonsence designed to instill fear amongst them.

During the Sinestro Corps. War, the Scar would be badly burned and killed by the Anti-Monitor, although it appeared she had survived. Following the War she would slowly but surely come to realise her true alliegance, and begin weakening the Corps. from within.

War of Light
During the War of Light, Scar would be instrumental in manipulating several facets of the Corps., and deceiving her fellow Guardians into making decisions that would ultimately lessen the trust between them and their own Corpsmen.

These actions included:

During this time she would personally travel to Earth and give the first Black Ring to a recently self-murdered Black Hand, resurrecting him as the tether between the world of the living and the unliving.
 * Intentionally sabotaging a diplomatic mission to Zamaron, where she was aggressive and dismissive of the Zamaron's methods. She would, following this, suggest and create a law that forbade romantic relationships between Green Lanterns, leading to over some 200 lanterns resigning.
 * Leaking information about the Green Lantern transfer of Sinestro himself to Korugar, therefore allowing him to be rescued before execution.
 * Appointing two Lanterns to seek out the Corpse of the Anti-Monitor without the knowledge of her fellow Guardians.
 * Remain behind during the Guardian led mission to Okaara to confront Agent Orange. During this time she would facilitate a breakout within the Oan Sciencells that would cause the deaths of many prisoners and Lanterns, and intentionally blocked Sodam Yat from accessing the Ion Power while on Daxam, forcing him to fly into the Daxam sun.
 * Upon the Guardians returning to Oa, she would order that all of the inmates that participated in the riot be executed by the Alpha Lanterns, therefore making more corpses for the black rings to latch onto when the Blackest Night came.

While the Guardians looked upon the universe, and realised that despite their attempts, they could not stop the War fo Light from coming, Scar sensed the Black Lantern Central Power Battery activating on Ryut. The Guardians, sensing danger, proposed to order a Code Black, which would recall all Green lanterns to Oa. Before they could do so however, Scar killed one of them, and immobilised the rest using black ooze. As soon as she was sure that Oa was completely under seige, she teleported herself and the Guardians to Ryut, and then them and the Black Battery to Earth, where Black Hand summoned Nekron, Lord of the Unliving, to the mortal plane.

During the Blackest Night, Scar would remain near the Guardians to ensure no one freed them, injuring the three Flashes in doing so, before being attacked and eventually destroyed by the Corps. leaders, including former bretheren, Ganthet and Sayd.