As most of you reading this will know, Jason Todd is the Arkham Knight. However his origin story provides little detail on how he convinced the established villains his quality. That is the precise reason I think he should have a dlc showing how he proved. This would be part of the Gotham city stories dlc.
This DLC would help portray Jason and his hate for Batman in a more focused light. He also is a moody guy which wouldn't exactly get Scarecrow on side. It could also show how he forged an alliance with Deathstroke.
The story would be very interesting. It would show Jason's stunning fighting ability which wasn't on show for the main story unfortunately. It would most likely be Penguin and Two Face pitting him against their best men in hand to hand and predator missions while also testing his intelligence as a commander. The twist is if Jason loses in these fights the thugs have permission to kill him.
Jason has has many gadgets as Batman. Despite only having 3 in the Red Hood story pack. There is only reason he can't have explosive gel or a disruptor. Also if this happens I really hope Rocksteady would give us a sniper rifle as using that would really give us a new perspective on Arkham Knight and the series as a whole.