The Superman of Earth-Two breaks open a portal to the DC Universe, and the four residents of the paradise dimension return, making themselves known to Power Girl and Batman. When introduced to Power Girl, he calls himself Superboy-Prime for the first time. Kal-L tells Power Girl: "When the universe was reborn, Earth-One became the primary world. The scraps of the remaining worlds were folded into it. But I finally realized—we saved the wrong Earth". Superboy-Prime is jealous of Conner Kent, the modern Superboy, believing him to be living the life he himself ought to have had while not fighting for it. He also believes the Earth's heroes act more like villains. Superboy-Prime confronts Superboy, telling him that he (Superboy-Prime) is the only Superboy the Earth needs. Superboy-Prime brutally attacks Conner, but not before Conner activates his Titans homing signal. The Teen Titans, the Doom Patrol, and the Justice Society of America arrive to help Conner. After accidentally killing Pantha with a deadly punch, Superboy-Prime is left shocked and horrified while the heroes try to contain Superboy-Prime, who kills (Wildebeest and Bushido) or wounds (tore Risk's arm off and badly beats most of the rest) several others.