Every DC hero begins as their well-known self — Superman as Superman, Batman as Batman, Green Lantern as Green Lantern, etc.
But twenty years later — each character has developed into his or her own greatest villain.
Superman now rules the world from the shadows, imposing his own moral code on Earth with an iron fist. He’s Lex Luthor, if Lex Luthor actually had super-powers.
Batman is the world’s only true insurgent. He’s still a brilliant tactician and strategist with plans inside of plans inside of plans, but his sanity has long since shattered, leaving him a maniacal, cackling nihilist and a symbol of humanity’s uncontrollable pathos.
Wonder Woman has usurped the throne of Ares on Mount Olympus, taking his place in the Pantheon as Diana, Goddess of War. Paradise Island has long since been laid to waste, and the Amazons destroyed.
The Flash has vanished into the time stream years ago, and is now on a Sisyphean journey to repeatedly alter the past and right the wrongs of the present, confronting his former self over and over again only to be thwarted at every turn. No matter what he does, to alter time, it always corrects itself in the end.
Green Lantern began as a good soldier in the Guardians’ Green Lantern Corps, but has overthrown his masters and become the sole leader of the fearsome Parallax Corps. He fashions himself the sole “Guardian of the Universe” and imposes his will on all life. Maybe he even grows a Sinestro-stache, make him look like Errol Flynn a bit.
Haven’t thought of ones for Aquaman or Captain Marvel (sorry, Shazam) yet