Superboy - Season 3 Episode 6 Roads Not Taken (2)
Overview: Superboy jumps through the portal to escape the kryptonite assault. In this world, he is the "Sovereign," a dictator that rules using fear tactics. Lana and Luthor, lovers in this world, are leading a revolution to overthrow the Sovereign. Lana arms herself with kryptonite bomb to destroy the Sovereign, hurting both versions of Superboy. But when she sets off the bomb, killing them both, the first alternate Superboy rescues the original Superboy from the kryptonite-laden shockwave. When all is done, Superboy destroys the portal.