Villains United (2005) #6

Plot

Although vastly outnumbered in the battle between the Six and the Society, the Six get help from various sources- Solomon Grundy, who Rag Doll convinces to aid the Six; Knockout, who's been a mole for the Six in the Society; and Mockingbird who's true identity is revealed as Vandal Savage, later convincing Luthor to have the Society cease the battle or he will kill him. Cheshire is shot by Deathstroke as she surrenders, and Mike the Parademon sacrifices his life to save the Six during the battle. Pariah is killed by Luthor in the interim, so that he can't warn anyone of his upcoming plans.