

Depends on the timeline. There is one comic series where Jason does actually kill Joker.
But what most people tend to think of is Under the Red Hood from 2010, where Jason is kidnapped and beaten by the Joker in the beginning before supposedly murdered. He survives in secret, returns as the Red Hood, and at a confrontation with Batman discusses how he’s upset that Joker could kill him and that Bruce refuses to kill the Joker in return.
It’s a common theme. In another timeline one iteration of Selina leaves Bruce because he was willing to risk their lives to save the Riddler despite how he was entirely responsible for the situation that got himself killed.
You know who does kill Joker in a lot of timelines though? Superman. He usually ends up going a bit authoritarian afterwards but Bruce will even admit in some of those situations that Joker’s death is necessary.












Injustice was really solid as long as you focus on the main cast. I do think a lot of people were disappointed with how Damian was handled.
There’s also the Justice Lords, where Batman reluctantly complies with Superman’s regime and where Superman’s preferred method of punishment is lobotomizing villains.