Hidden in the Book of Oa is the forbidden chapter of Cosmic Revelations, which contains a prophecy called the “Blackest Night”. In the prophecy, seven different colored corps are at war with each other, eventually destroying one another and the universe.
Following the Sinestro Corps War, Ganthet and Sayd are banished from the Guardians. Realizing that the “Blackest Night” prophecy will come to be, they create a blue ring powered by hope. The remaining Guardians create the Alpha-Lanterns and reveal new laws they’ve written to the Green Lantern Corps.
During the Blackest Night, the Guardians finally realize the accuracy of the prophecy and are imprisoned by Scar; a rogue Guardian who launches an attack on the Corps by reviving deceased members as Black Lanterns. Command falls to Guy Gardner, Kyle Rayner, and Salaak, a senior Lantern holding the rank of Clarissi.
The Green Lantern corps, along with the other six corps (The Sinestro Corps, the Red Lantern Corps, The Indigo Tribe, The Blue Lantern Corps, Agent Orange, and the Star Sapphires), fight the black lanterns to regain safety and order in the universe.
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