The Arkham Knight

Intro The Arkham Knight was originally Jason Todd, the second person to take the mantle of Robin after Dick Grayson and before Tim Drake. He was thought to have been killed by the Joker. Jason had always possessed an explosive temper with numerous incidents of him going too far in his actions as Robin, despite his natural talents and aptitude under the Dark Knight's guidance, with hints in his behavior that he might one day kill instead of using restraint. Jason was held captive by the Joker in the abandoned wing of Arkham who kept him alive, and tortured him physically and psychologically through the The Joker continued to torture Jason for over a year, and during this time, Batman continued desperately searching for him but with no success, he eventually gave up. Meanwhile, the Joker was successful in breaking Jason, and finally convinced him that Batman was the enemy. When the Joker recorded an interview with Jason showing that he had broken him (with Todd going so far as to almost reveal Batman's secret identity), the Joker then shot him in the chest and stated that he didn't like "tattletales". The video was sent to Batman who presumed that Jason was dead after he witnessed him being shot. Jason was in the asylum before Deathstroke helped him with his escape. The Arkham Knight eventually found Scarecrow after he killed his men as a demonstration of his skills, advised him on how to take revenge on Batman, stated that he had access to an army trained in Batman's techniques, and knew exactly what he feared. It was the Arkham Knight who specifically gave Scarecrow the plan to drive the citizens of Gotham out in order to bring the full forces of his army into the city unchecked and where exactly that Scarecrow could do the most damage.