text: Sometime later, Batman fires Grayson for proving unsatisfactory, which strengthens the rift between the two, and they eventually part ways. In The Dark Knight Returns, Grayson is absent but mentioned several times. First, Commissioner Gordon asks Bruce if he has spoken with him recently, and Bruce coldly says he has not. Later, when Batman's new Robin, Carrie Kelley, rescues Batman and asks about his tank-like vehicle, Batman responds that "Dick called it the Batmobile", and later when Batman suffers a diabetic stroke, he desperately calls out Grayson's name. He is also shown talking to Grayson in his mind, such as when he calls the Mutant leader a "brand of evil we had never dreamed of." This seems to imply a sense of fatherly love otherwise not shown, or that Batman simply missed Grayson's company.
  In The Dark Knight Strikes Again, Grayson re-appears as a genetically altered supervillain. Sometime after his dismissal, he apparently joined forces with senior villains such as Luthor, and underwent extensive gene manipulation to gain a healing factor and shapeshifting powers, but at the cost of his sanity. At the behest of the government, Grayson begins a maniacal crusade to hunt down and kill as many superheroes as possible, but in order to conceal his identity and partly due to a twisted revenge scheme on Batman, Grayson takes on the appearance of the Joker, who killed himself in The Dark Knight Returns.