I honestly think Superman's Fall From Grace in the Injustice Universe would be considered the Injustice Batman's greatest failure.

Don't really believe that. That whole thing where Superman is somehow his Joker after everything and that Batman is responsible for the way Clark acts.

All of them apart from Jason Todd's death never happened in the main continuity.

This question isn't about the main continuity.

Ah ok I didn't read "Injustice" before "Batman" in the title. My fault.

Dick Grayson's death was Damian's fault, Batman was busy assisting Superman stop Grundy. On the other hand Joker giving Superman a bad life was definitely Batman's fault, because both Batman and The Joker knew that he wasn't going to redeem and will stay the same chaotic psychopath. Batman shouldn't have saved him every damn time.

Where did Joker kill the JSA? I wouldn't say that Dick's death is his failure considering the upbringing of Damian that had nothing to do with him.

@AFDurbin2 I suppose you haven't read year zero, that's where he almost kills the JSA

@AFDurbin2 I know I'm two years late to answer your question Basically there was a comic series released called injustice year zero.

it takes place the year before Joker gives Superman one bad day.

basically Joker uncovered this magic scarab that gave him near unlimited power which he used to mind control members of the JSA to kill themselves in horrific fashion. he also killed several members of the JSA during the final battle before being incapacitated and sent back to Arkham.

it's also revealed that the reason Harley Quinn stayed with the Joker was because she was trying to protect ivy and they're adopted daughter.