5 Directions Joker 2 Could Take
3. Old Man Joker
Building on the previous entry, the idea of The Joker growing old and decrepit is yet to explored in a live action movie. A time skip from the first film to present day places Arthur Fleck in his seventies, with all sorts of mischief in between to reflect on. Sure, he could sit in Arkham the whole time, but we know there's no facility that can hold him for too long.
With age comes the deterioration of both body and mind. The Joker's not a man who gets work done physically, it's his relentless insanity that drives him. Watching a senior citizen Arthur Fleck lose total grip on reality - while still trying to be a self-fashioned criminal mastermind - creates a space in which his psychology can be explored properly.
Joker as a film is focused on the external. It deals with the effect of society shunning people in need of help and the monsters that sort of negligence creates. Joker 2 can flip the script with an internal focus. Arthur's had nothing but time to grow the Joker mythos. Towards the end of his life, he can look back on the horrors he's committed and feel a sense of accomplishment. He's been a menace for so long and essentially got away with it, filling in the blanks of what he got up to with the underbelly of Gotham city.
At this point, the older Fleck must pay for his sins. This can be done in all manner of ways. Hell, one final punch-up with an aged Bruce Wayne (Michael Keaton, anybody?) wouldn't go amiss. A life of making things miserable for others can't go unpunished, so seeing Fleck's generation-spanning brand of chaos via flashbacks sets up his demise as a veteran of the crime world.