"Changing the Guard!" Story by Ron Marz. Art by Darryl Banks and Romeo Tanghal. A new Emerald Era begins! Hal Jordan has destroyed the Green Lantern Corps, murdered Sinestro, and seemingly absorbed the infinite power of the Corps Battery. Now, there is only one Green Lantern in the whole universe. A neophyte hero with no one around left to teach him how to use his amazing abilities. And he sure could use the help, as a new villain by the name of Ohm arrives on the scene, and the sinister Mongul returns to finish the job he started with Coast City.