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 Beyond: Return of the Joker disfigured him to look like the Joker, and tortured him for three weeks, at which point Tim revealed Batman's secrets. After the Joker sadistically taunted both Tim and Batman himself, Batman furiously attacked the Joker in retaliation. During the final battle, although the Joker attempted to make Tim kill Batman, Tim turned on the Joker and killed him before suffering a mental breakdown; Harley Quinn is also believed to have perished after falling from a mineshaft during her fight with Batgirl (Barbara). Batman and Batgirl comforted Tim and then buried the Joker's body in the mineshaft deep beneath Arkham Asylum.