Doomsday Batman!

"Joker!!!" A suppressed roar, furious beyond all limits, rang out. Within Batman's wildly expanding body, muscles swelled and burst one after another, spraying streams of blood. Batman roared madly. At last, he stopped holding back and took out the ultimate weapon he had prepared many years ago. It was a vial of serum—a vial of Doomsday Serum. Many years ago, when Donnie was still on Earth, he had suddenly acted and killed Lex Luthor.