 First formed by the banished former-Guardians Ganthet and Sayd, they are based on the planet Odym (later Elpis) and their powers are fueled by the emotion hope.The Blue Lantern Corps is rooted in the events that transpired during the "Sinestro Corps War" story line.During the first half of the event, Ganthet and Sayd serve as a dissenting voice among the Guardians as they acknowledge that the Blackest Night prophecy within the Book of Oa is coming to pass.