Lady Gotham, still reeling from Joker's latest grand attack on her city, which claimed over 3,000 lives due to strategically placed explosives, gets completely fed up. She leaves for the Infinite Realms to expedite her healing and demands that Danny, as the High King, do something about the Joker, claiming 'No punishment that can be doled out by mortal hands is severe enough for all he's done!'
She tells Danny about everything he's done to her knights, Bruce, Dick, Barbara, Harper, Luke, Kate, Jason, Cass, Tim, Steph, Duke, Damian, all of them. She sobs about all her children who have died or suffer(ed) greatly at his hands. Danny, after hearing her story, agrees to help her.
Now, Danny is too busy as the High King to handle it himself. Especially since he isn't taking time off to see his friends and family, who all eventually died and came to live with him in the Realms. So instead, he has his children do it for him. Ellie and Dante are so happy to finally have something fun to do, and if it means striking fear and regret into the splintered soul of a clown who hides behind his insanity to get away with horrible crimes against the living and dead, then this hunting season just got a whole lot better. Ellie very joyously tells Danny 'I told you so' when they get this assignment, Skulker's lessons did come in handy after all! Lady Gotham promises to hide the prince and princess from her knights for as long as possible.
The Bats, and the JL and JLD, get involved, of course. But they just can't pinpoint who or what is after the Joker, and a remarkable number of them, especially most of the Bats, find they don't really care, since the Joker hasn't caused trouble since that giant bomb fest he had a month or two ago, even if he keeps drawing their attention to him to beg for help.
Ellie and Dante's goals are clear, make the Joker as afraid and paranoid as possible and to figure out what plan/failsafe he has in place in case he dies, shut it down, and shatter what remains of his soul and scatter the pieces across dimensions and timelines. Its just a natural consequence that they're enjoying it as much as they are.
