10 Comics Heroes Who Lost Themselves (But Saved The Universe)
9. Superboy (Conner Kent) - Infinite Crisis
The clone of Superman and Lex Luthor, Superboy's career has been brief, but nearly as impactful as those of his famous fathers. The young Kryptonian has grown from a wannabe Superman replacement to a hero in his own right, and accomplished a great deal since his debut.
This, coupled with his endearing nature, made it all the more devastating when he sacrificed himself to save the multiverse in the Infinite Crisis crossover. The epic tale sees alternate versions of Superman, Lex Luthor and Superboy attempting to recreate the universe to fit their own misguided standards using a tower built from the remains of the Anti-Monitor.
The alternate Superboy (Superboy Prime) attacks his counterpart on several occasions, believing him and his fellow heroes to be pale imitations of actual heroes. Greatly outmatched by his more powerful counterpart, Conner throws everything he has at Prime and destroys the tower in the process. This puts an end to the villains' machinations but the blast is too much for Conner, killing him.
The Kryptonian was later brought back by the Legion of Superheroes to face off against Prime in the 31st century, and later returned to his own timeline.