Doing some video clip hunting for the final project lead me to Gotham, and that series had some great moments but any scene with Jerome Valeska is a good one. But in a scene where he walked into a nice building with a clean suit and a shotgun to talk business got me thinking. Primarily about the Joker and his mask.
By this point its safe to say that there is a mask in the world of criminals, either the one for your family or the one for your enemies. What is fascinating about the Joker, to me personally at least, is he becomes the mask. The very identity of the Joker, whether it was just a diversion or some mistake becomes the defining piece of the man who becomes the Joker.
In a similar vein, this is Gatsby. He ignores who he was in favor of what he wants to be, believing a lie over the truth. Criminals like Al Capone or Tuco Salamanca can place the mask on or off depending on when they need it, but men like Gatsby and the Joker become so used to wearing it, it becomes their true face.