Our Worlds At War In A Nutshell (2001)

The son of Mongul appeared to train Superman for the coming of Imperiex. Mongul Jr. himself appeared to perish in the struggle that followed, but he inexplicably turned up alive years later. Topeka, Kansas was destroyed by an Imperiex probe. Super-heroes, alien refugees, and New Gods rallied against the threat.

Strange Visitor and/or Kismet sacrificed her/their “life” while merging with Superman into a virtual exploding bullet to kill Imperiex. Brainiac-13 absorbed the energy released into his own Warworld, so now everybody had to fight him. Steel helped in his Entropy Aegis forged from the armor of a downed Imperiex drone by Darkseid. Martian Manhunter aided in the telepathic transmission of a new strategy.

The Amazons of Themyscira physically threw Paradise Island at Warworld for reasons and by means too ridiculous to elaborate upon. They also attacked Brainiac-13 through the sheer power of their love channeled through Darkseid into Tempest. Again, you don’t want to know, and yes, it was all the idea of a very gay creator passionately devoted to popularizing the Amazon heroines, Tempest and, apparently, the Care Bear Stare. Yes, it is not P.C. to even hint at "gay" as a pejorative, but I'm not taking it back.

Superman dove into the heart of the sun, powered up, and pushed Warworld/Imperiex/Brainiac-13 through a portal in space/time to act as the Big Bang itself. Oh, and Lena Luthor became a baby again, and as such has barely been seen or mentioned again. Hopefully the Contassa took her back.

Further casualities would include Sam Lane (father to Lois,) Hippolyta (mother of Wonder Woman, when not in the role herself,) Maxima, Strange Visitor, Massacre, Doomsday (who was later regrown from the skeleton by Lex Luthor,) Mongul (who just turned up “better” years later,) Steel (on whom the Black Racer took pity and revived,) Lil’ Lobo (who replicated and evolved back into regular Lobo,) and a duplicate of Impulse (don’t ask.) So basically, as long as you weren’t a super-heroine or a forgettable supporting cast member, the whole mess rolled right past you. Three more women for the refrigerator, and a fourth if you count Mongal’s being murdered by the returned Mongul in her first appearance since OWAW (five years after the fact.) You really shouldn’t though, as there's neither woman nor male whose life had ever been touched by Mongal who didn’t wish on her death both brutal and swift.