“THE SON OF SUPERMAN” Chapter Three: In #3, with a touch that means death, the Eradicator proves he’s a match for Superman, but his super-powered offspring may be more than anyone can handle—including the Man of Tomorrow.

The Eradicator has arrived and he's after the Kent family. Can Superman put a stop to it?
Synopsis

Clark and Lois bring their son to the Fortress of Solitude, because their they have access to Kryptonian tech, which they need in order to find out why Jon is still unconscious (after the fall he took back at the barn).

Having entered the Fortress, the first person they stumble upon is the Eradicator. Clark, surprised yet furious, attacks him while asking him how he broke into the Fortress. Lois tells Clark to stop, the walls are already cracking. The fight between the two continues and the walls start collapsing. Lois and Jon are in danger and as the wall collapses, it is the Eradicator who saves them in time. Clark is quite surprised by this and the Eradicator tells him to settle this somewhere else.

Eradicator tells Superman that the Kryptonian race is the one true race. His goal is to preserve the purity of the race. Since Jon is half human and half Kryptonian, he would need to eradicate the "impure" half. After this conversation, Eradicator heads over to Jon and as he opens his mouth to eradicate him, Krypto jumps at the right moment in front of Jon, thereby sacrificing himself. Superman doesn't hold his punches, as he beats him continuously without taking a break. Jon is mourning Krypto's death for a wee bit, stands up consumed by rage.