The Devastator, also known as The Destroyer, is a villainous version of Batman from the DC Comics universe. He is a member of the Dark Knights, a group of vigilantes from the Dark Mutiverse whose goal is to assist the deity Barbatos plunge the central DC Multiverse into darkness.
The Batman of Earth -1 had always been weary of trusting Superman, fearing that one day he would go rogue. Unfortunately, Batman’s fears would become reality when Superman suddenly murdered Lois Lane and began slaughtering people for no apparent reasoned. The Caped Crusader hoped that he'd find some explanation as to why Superman would turn on them so he could somehow save his friend, but was unable to before he was forced into fighting the Man Of Steel himself.
Batman fought Superman with a Kryptonite-tipped spear which was soon disposed of when Superman amputated the arm Batman clutched his spear in. Superman then expressed his disappointment that after all the debates over who would win in a fight between the pair, a spear was the only thing Batman had to fight him with. However, Batman soon revealed that the spear was just to draw attention away from his real weapon; a modified Doomsday Virus that he then injects into himself. After transforming into a gigantic Doomsday-like creature (which regenerated his missing right arm in the process), Batman proceeds to pummel Superman before pushing a spike through his chest, killing him.
Batman’s victory came at a cost however, as the Doomsday Virus began to spread across the planet and transform everyone into mindless, rampaging monsters. With Batman unable to stop the spread of the virus and the world nearing it's end, he accepted an offer from The Batman Who Laughs to join the Dark Knights and became known among the group as The Devastator.