As Batman releases poisonous gas into the dome containing the invading aliens, the Green Lantern Corps arrive to stop him; with Hal Jordan himself going after Batman as the rest of the corps attempt to open the dome and extract the gas.
As Batman is confronted by his future self, Hal Jordan manages to convince him on why his actions were wrong as the aliens use the breach made by the corps to resume their attack and Luthor suddenly engages in a scientific theory that causes Future Batman to vaporise.
Batman, instead, opts to unite the aliens under the one cause to fight Brainiac alongside the Green Lantern Corps.
"If I can help three billion to live...what happens to me won't matter." — Batman