In the events leading up to this final episode, Bruce Wayne, both as the playboy billionaire and as Batman, had either befriended or used John, first to get out of Arkham Asylum, then more recently, to infiltrate a gang of super villains containing Harley Quinn, Riddler, Bane, Mr. Freeze, and Catwoman. When The Pact's immediate plans fell apart, John and Harley were confronted on Gotham Bridge with Waller's agents surrounding them. How you handled that pivotal moment not only changed how the Joker was born, but also what he feels his purpose is. Also, and this is no small feat on Telltale's part, that choice makes for completely different story in this final episode. I haven't seen the company put out such a drastically different gameplay experience before, and that includes the final episode of Guardians of the Galaxy whose level of branching points was already outrageous.