Justice League Dark concept art reveals the movie that might have been Last summer, filmmaker Joseph Kahn (Torque, Detention, Bodied) revealed that he had previously pitched on the long in-development Justice League Dark and offered a sneak peek at an animation test he had created to show Swamp Thing in action. Now, the director has taken to Twitter to reveal even more about his rejected pitch for the film, including pieces of concept art he had created along with his “wishlist” actors for the various roles.