Black Lantern Power Rings were weapons wielded by the undead ranks of the Black Lantern Corps and created by the powerful cosmic entity known as Nekron, Lord of the Unliving. These Black Power Rings were formed to be unleashed in the prophecised event known as The Blackest Night which stated that "The Dead Will Rise" with all the enemies of the Guardians of the Universe rising up to destroy them and their Green Lantern Corps. Following the Sinestro Corps War, Nekron began to work in the shadows to bring about the fulfillment of the Blackest Night Prophecy. His first act was the imprisonment of the Anti-Monitor on Ryut in Space Sector 0666 and forming him into the Black Lantern Central Power Battery from which the Black Power Rings would emerge. He also had the corrupted Oan Scar work subtely in bringing about his plans.
Powers
The Black Lantern power rings have the ability to animate the dead, although how this is accomplished is unclear. The ring does not animate corpses, but appears to forcibly resurrect the spirit of the victim into corporeal form. As a notable exception, when Boston Brand of Earth was resurrected, his disembodied soul, known as the superhero Deadman, was left behind, trying to possess his former body but unable to enter it because of a powerful personality, mirroring darkly his own, already possessing it. The Black Rings however are known to have resurrected individuals whose bodies were long since destroyed or decayed, such as Tomar Re and Ch'p of the Green Lantern Corps, Firestorm whose body disintegrated during the Identity Crisis and the original Aquaman, whose body was warped into a monstrous, amnesiac, marine life-form with a watery arm before death and was brought back as his more recognized, humanoid, self.
Individuals resurrected by the rings are fueled with a hunger for the hearts of the living. A Black Lantern ring is charged by .01 percent for every heart claimed by the bearer. The reanimated individuals retain the powers they had when alive, but it is not yet known if resurrected Green Lanterns (or members of other Corps) have the ability to create constructs and other effects as they did when they wielded their original power rings.
Members of the Black Lantern Corps exhibit corrupted versions of their original personalities, often goading or tormenting their victims with comments referring to their past friendships and associations.
Black Lantern rings emit a sound similar to buzzing flies when searching for victims to resurrect.
Weaknesses
This far only one individual, Don Hall (the original Dove of Hawk and Dove) has escaped resurrection by a Black Lantern power ring. When the ring attempted to recruit him, it was destroyed and the words "Don Hall of Earth at Peace" were heard. This would seem to indicate that a person who dies in a state of complete peace with himself cannot be recruited as a Black Lantern. Dawn Granger, current Dove and successor of Don, similarly found herself resistent to assimilation: since the Black Lantern need to discern one of the seven main emotions in the heart they're stealing, Dawn Granger, whose heart balances the seven emotion in a white, unreadable aura, is unfit to replenish their rings.
It's actually revealed that the only main weakness of the Black Lantern is the White Light, the pure, uncorrupted light of Creation who was splintered at the dawn of times into the Seven Lights of the Emotional Spectrum. Thus the Indigo Tribe, whose coral staff can combine one or more lights, hold the power to destroy single black rings by striking them with a burst of Indigo Light replenished by another Power Ring, but only the combined power of the Seven Corps could destroy the Blackest Night itself.
