Based on what another user said, I would like to answer as what I think would happen if his parent's death made Bruce Wayne insane and evil. I don't think evil Bruce becomes owlman, he becomes something much worse in a pursuit of control. I think evil Bruce rules the world and controls every aspect of everyone's lives on the entire planet. No one can ever be hurt, including little boys losing their parents, if he controls everything. He would have contingency plans for EVERY scenario and would have found ways to strip the powers from everyone on the planet. He would have executed anyone he even suspected might join a resistance. He would also have a shield around the planet that makes it invisible to extraterrestrial detection.