7. The Batman Who Laughs (Bruce Wayne Earth-22)
First appearance: Dark Days: The Casting No. 1 (2017)
What makes this Joker so special? In Earth-22, the Joker was dying, which is why he brought great chaos to Gotham. He forced Batman to witness how he killed many people in Gotham, similar to his own fate. Batman became angry and killed him. However, the Joker spread toxin with his death and poisoned Batman.
Slowly, Batman transformed into the Batman Who Laughs. He killed not only his family but also many heroes of Earth-22. He became acquainted with Barbatos, who showed him the dark multiverse.
Through Batman’s intellect and the Joker’s madness, the Batman Who Laughs became a powerful entity that threatens the multiverse.
Technically, this is not a Joker variant, but a combination of Batman and Joker is probably the most terrifying thing that can happen to the universe (DC Database).
Though it is quite unlikely that the upcoming live-action films of the DC universe will feature any of these Joker variants, the animated film series makes anything possible. In the comics, new versions of well-known heroes constantly appear, also in the Absolute Universe: New story makes Batman even darker, even takes away his strongest weapon: money
