Batman: White Knight stopped with a fist, i.e. Batman's methods. This led him to turn the Joker into a politician, using the character's intelligence and charisma to win the people of Gotham over. DC Comics had no problems with the ideas that Murphy had for the series such as changing the timeline in Batman's history. However, the adult content like nudity and profanity that Murphy had intended to include were not permitted. Murphy revealed that the Joker in "White Knight" has the real name Jack Napier, a callback to Tim Burton's 1989 "Batman" film where the Joker played by Jack Nicholson also shares
Batman: Arkham City rejuvenating Lazarus Pit before the Joker can use it. As Batman debates curing his foe, Joker attacks him, causing the antidote vial to inadvertently smash. Batman admits that in spite of everything Joker had done, he would have saved him. After Joker finally succumbs to his illness and dies, Batman carries his body out of Arkham City. As Commissioner Gordon asks what happened, Batman places Joker's body on the hood of a police car and leaves in silence. Rocksteady conceived the idea of a sequel before development of "Arkham Asylum" had concluded, developing ideas for both the story and setting