>>212651127 (OP)Have the director refuse to make it, because a sequel never made any fucking sense anyways.
Failing that just shamelessly rip off King of Comedy, have the whole plot be Joker escapes and holds some tv crew hostage and broadcasts some variety/talk show where him and his followers just do unhinged shit while the police try to find a way to stop him and save the hostages.
Maybe have a moment where he tries to unironically do his standup act and it bombs with the followers just confusedly staring at him, and he gives up and just shoots someone to get a reaction out of them but he's clearly kind of upset about it for the rest of the movie.