Regrouping after the failed initial attack, the united heroes mass within the Batcave where Luthor creates advanced sets of armour for the second attack. However, during the attack Brainiac takes control of Luthor's robotic body and uses him to kill the heroes, including Superman who returns in an attempt to stop Luthor. When Brainiac, thinking that he no longer needed them, killed his allied army of villains, Luthor reveals his ruse and the heroes, thought dead, arise and re-initiate their attack.
"He played his hand. It's time for us to play ours!" — Lex Luthor