Green Lantern was a hero of Earth, who fell into a trap laid by Barbatos. His body was destroyed, and his mind and soul were enslaved with his ring animating a new form for himself as the Death Construct.
Featured in these Comics
Other Personas of Hal Jordan (Dark Nights: Metal)
History
Green Lantern and the Justice League stood against Barbatos' invasion of the multiverse. However, when they attempted to don armor made of Element X to battle him, they found it corrupted. The armor enslaved the heroes to Barbatos, with Green Lantern losing everything but some replica of his consciousness contained within his ring. At Barbatos' command, the ring created a monstrous shell called the "Death Construct".
For two years, these Dragons of the Bat waged war on what was now called "Earth-Metal", until the returning Duke Thomas, now called the "Last Monitor", rallied the remaining heroes of Earth-Metal to stand against the Dragons. The Death Construct battled The Flash, who reached into the energy shell and stole Hal's remaining hand away, destroying the Construct.
