Love him or hate him, Deathstroke's dispatch of the entire Justice League was badass. His only mistake was attempting to take the Guardian Ring from Kyle Rayner, giving Oliver time to stick his shaft in Slade's bad eye. (That Came Out Wrong)
Deathstroke's analysis: Zatanna is the most dangerous member of the JLA.
When he gets his memories back, Doctor Light calls out the Titans. He gets all of them, past and present, two or three dozen◊ superheroes in all. His response◊?
Doctor Light: Well? What are you waiting for, Nightwing? I know you're dying to say it.
Dr. Light sitting on a throne-like chair, and in the last panel of the page, looking directly at the reader as if to say, "I'm back." Chills.
Similar to Dr. Light, the reinvention of the Calculator comes out to this. He was formerly a supervillain whose schtick was to use Awesome by Analysis to intentionally get his ass kicked in a fight with a superhero, as once that happened, that specific hero could never beat him again — except, of course, thousands of heroes exist, and he went to jail after each defeat. Identity Crisis remade Calculator as a Knowledge Broker who plausibly keeps a few steps ahead of Batman, and whose mercenary tendencies don't preclude a fondness for some of his colleagues. The series refers to him as a Gender Flip version of Oracle.