Draft:Joker (Arkhamverse)

Joker, whose real name is unknown, is a fictional supervillain voiced by Mark Hamill and Troy Baker in the Arkhamverse, based upon the character of the same name. Named for his comedic persona and appearance, which takes the appearance of a clown, he is in fact a sociopathic, manipulative, mass murderer who is responsible for the deaths of many throughout the series.

His death at the end of Batman: Arkham City has been heavily praised and frequently listed as one of the most shocking plot twists in gaming.

Batman: Arkham Asylum (2009)
He is introduced in Batman: Arkham Asylum (2009) as a patient of Arkham Asylum. After the Joker assaults Gotham City Hall, he is caught by Batman and taken to Arkham Asylum, which temporarily houses many members of the Joker's gang, who were transferred after a fire at Blackgate Prison. Believing the Joker allowed himself to be captured, Batman accompanies him into Arkham Asylum. The Joker's plan is revealed as Harley Quinn takes control of the security and the Joker escapes into the facility.

The Joker threatens to detonate bombs hidden around Gotham if anyone tries to enter Arkham, forcing Batman to work alone. Batman learns that the Joker returned to the asylum to gain access to Young, who has been developing TITAN—a more powerful version of the Venom drug that gives Bane his strength. Young learned that the Joker had been secretly funding her research to create an army of superhuman henchmen; her refusal to hand over the formula precipitated Joker's return to the asylum. A bomb kills Young and the Joker obtains the completed batches of Titan.

At the end of the game, the Joker announces that the preparations for "his party" are finally complete and Batman confronts him. The Joker reveals he has recaptured Gordon and tries to shoot him with a TITAN-filled dart; Batman leaps to Gordon's defense and is shot instead. Batman attempts to resist the change, and an upset Joker takes an overdose of TITAN, mutating into a massive monster. They go to a makeshift arena on the building's roof, the Joker challenges Batman to a fight as Titan-induced monsters in front of news helicopters. Batman refuses to transform, uses the antidote on himself, and defeats the Titan-affected Joker and his henchmen. In the aftermath, those affected by Titan begin to revert to normal, including the Joker—who is taken into custody as police officers retake the asylum.

Batman: Arkham City (2011)
In Batman: Arkham City (2011), it is revealed that the TITAN formula caused mutations in Joker's blood, gradually killing him. Joker captures Batman and performs a blood transfusion on him, infecting him with the same fatal disease. Joker also reveals that Gotham hospitals have been poisoned with his infected blood. A cure is eventually discovered by Batman. However, as Batman debates curing his foe, Joker attacks him, inadvertently causing the antidote vial to smash. Batman admits that he would have saved him despite everything Joker had done. Joker finally succumbs to his illness and dies. Batman carries and places Joker's body on the hood of Commissioner Gordon's car before leaving Arkham City in silence.

Batman: Arkham Knight (2015)
Except for his cremation, Joker does not physically appear in Batman: Arkham Knight. However, his infected blood was used in blood transfusions, infecting five people, including Batman. Concealing his infection, Batman imprisoned the four other patients, who were physically and mentally transforming into the Joker. The Joker, existing as a mental projection produced by the infected blood and fear toxin, frequently appears to taunt Batman and twist his perception of reality.