Set within the new DCU (James Gunn's universe), this film or series arc establishes the Joker not as a rising criminal, but as the "Clown Prince of Crime" who has plagued Gotham for over a decade. He is an established nightmare—a criminal mastermind who views his conflict with Batman not as a war, but as a twisted romantic comedy of violence. The story shifts the dynamic: Batman now has a biological son, Damian Wayne (Robin).
The Joker, feeling replaced and jealous of this new "sidekick" taking Batman's attention, orchestrates a psychological campaign to break the boy. He doesn't want to kill Damian; he wants to mold him, to prove that even the son of the Bat is just "one bad day" away from becoming a monster. The narrative is a psychological horror-thriller that takes place over a single Halloween night in Arkham Asylum, which Joker has silently taken over, turning it into a funhouse of traps designed specifically to test the bond between father and son.
