Arkham City Robin: Arkham City Robin is clad in a heavily modified version of the original costume which retains a similar color scheme while incorporating segmented body armor and an overlapped yellow-lined hooded cape. Having been trained by Batman as well as master combatants, Robin is further benefited by inordinately honed deductive skills which enable him to discern the precise weaknesses of his opponents. The Arkham City version of Robin is characterized as a more brutal fighter.
Joker: The Joker is clad in his garish purple tuxedo. The Joker’s original penchant for comical stunts and outlandish murders eventually becomes a murderous obsession with his arch-nemesis, Batman. Though the Joker lacks any formal hand-to-hand training, his sharp reflexes, unpredictability, and his arsenal of gimmick-based weaponry enable him to battle against Batman with varying degrees of success; the Joker’s weapons vary from acid-squirting boutonnieres to electrocuting joy-buzzers to mass-deployments of his Joker venom to which he himself is completely immune.