Batman/Superman Vol. 2: Game Over (The New 52)

The Dark Knight and the Man of Steel uncover a plot by the Toymaster to use a secret, potentially deadly element in his new video game, the characters created by players manifest in real life. The ultimate fighting game results--and a world-wide network of players must team up to create the most powerful, skilled Super Heroes imaginable with one goal: To kill Batman.
When Batman and Superman are corned by the Toymaster and Mongul, they are pitted against on another in a battle to the death, with their only hope being the The Worlds' Finest.