Batman probably still holds himself responsible, he’s usually able to block out mental attacks (not saying he is responsible though, just that he probably sees it that way)
Who would break Batman easily Joker his arch nemesis of many years and is a crazy calculating threat that is obsessed with Batman and knows everything about him,(Not identity). Or a Goofy ghost
To be fair to dead man he was originally a normal human so the only type of body he was probably confident in using was batmans. Imagine he used too much strength as superman or wonderwoman and just busted through the building or planet
Why not just possesses the Superman and get in the path of the bullet blocking it, or the villain and shoot upwards, or the monkey and jump on Wonder Woman, or Wonder Woman and duck?