Kingdom Come/Fridge


 * Fridge Brilliance: At the end, the Silver Age villains who formed the "Mankind Liberation League" to exploit the superhuman conflict receive a bout of Laser-Guided Karma by being forced to work in Bruce Wayne's hospital at the end. Notice, however, that a further level of of Karma is active in what duties they've been assigned; would-be world conquerors and mass-murderers Lex Luthor and Lord Naga are assigned demeaning roles like mopping floors and emptying chamber pots, while relatively low-level thieves like the Riddler and Catwoman get relatively minor jobs.
 * Another, not mutually exclusive possibility: those with some degree of compassion (Catwoman) or at least no desire to cause harm to innocents (Riddler) work with patients, while the murderous ones are given jobs that don't put vulnerable people within their reach.
 * Fridge Brilliance, in a meta sense. The event that forced Superman et al. out of retirement is the destruction of Kansas, which was caused by the death of Captain Atom. Captain Atom is somewhat obscure, but much better known is his Captain Ersatz: Dr. Manhattan. Just one of several interesting ties between the story that launched The Dark Age of Comic Books, and its best-known Deconstruction.