system
Given the following post, respond as if you're commenting on Reddit:
human
[Injustice] What, if anything, could someone have done to prevent Superman's fall after he killed the Joker?
gpt
Three things could have stopped Superman.

The first is to keep the Injustice version of Wonder Woman away from him, unlike the Prime Wonder Woman, she has a much clearer bloodthirsty streak ("explained" by her version of Steve Trevor being an actual Nazi) and she knowingly kept some comforting words from Superman, knowing it might have softened him.

The second, Hand over Harley Quinn, maybe not directly to Superman, but to some from of law, Batman kept her hidden, the knowing accomplice to Jokers Genocide of Metropolis, yet, strangely nobody talks about that, her getting some form of justice might have stopped Superman in his tracks, as then both Lois, Jimmy and Metropolis would be avenged.

The Third is much more simple, but a whole fuckton more finger pointy, Batman, Batman shut himself off from Superman for violating a principle Batman has, no killing, even for a scumfuck who just murdered over 11 million people including Supermans best pal, his wife and unborn child. If Batman had came and comforted his supposed closest friend, who had made a rash choice in a moment of utter despair and anger, Superman might have cooled off, but no Bats had to go all broody and crap.