Action Comics #836

As they battle on the deserted Earth-2, the two Supermen live out each others' lives with every punch. Kal-L finds himself at the beginning of Kal-El's career, armed with the knowledge of the darkness looming in the future. With a surgeon's precision he acts to try to cut it off.

But when the Justice League deems his measures too extreme, Superman forms another team... the Justice League Elite!