Earth-423 (pre-crisis)

Earth-423 (pre-crisis)

Multiverse characters: 

Superman, Batman, Lex Luthor, Brainiac, the Legion of Super-Heroes, Krypto the Superdog, Captain Marvel, Superwoman

Notes: 

Superman fought a final battle with his enemies and disappeared

The last DC "imaginary story"

Known as the Superman: Whatever Happened to the Man of Tomorrow? storyline

Named in Crisis On Infinite Earths: Absolute Edition (November 2005)