The following contains spoilers for Young Justice: Phantoms, Episode 21, "Odyssey of Death!" now streaming on HBO Max.
On Young Justice: Phantoms, Superboy's journey has been quite harrowing. Conner Kent was thought dead, after a Kryptonite-laced explosion on Mars, only for the show to reveal he was stuck in the Phantom Zone. It was all part of Lor-Zod's scheme to kill Superboy, erase the Legion of Super Heroes from the timeline and free General Dru-Zod's cult with a projector from New Genesis.
However, what made the journey even more terrifying was that while he protected Phantom Girl in this cosmic prison, Superboy was losing his mind. It was a shame because he always wanted to celebrate his identity as part of the House of El, but sadly, "Zone Sickness" was taking this away. Unfortunately, thanks to the latest episode's horrific moment of devotion and the reconciliation of dark events prior, Superboy may end up killing DC's most important heroes down the line.
Seeds were planted when Lor opened a rift from New Genesis to pull his dad over. Superboy jumped up and grabbed the villain, though, thinking he was going to his death. Zod insisted this was an escape, berating Conner, but Superboy maintained he'd protect his leader. Eventually, the portal was closed, and they fell back into the Zone, leaving Zod stunned over Superboy's loyalty.
It's reminiscent of Ursa, Non and Faora's worship, confirming Superboy is ready and willing to die for Zod. Give how Zod's forked tongue got him to stay in their community, it's easy to envision the villain now programming Superboy to murder if the need arises. And it may well happen should Zod figure out he's a clone of Superman. Once Zod susses out the emotional attachment, he could easily send a brainwashed Superboy, should they escape, to kill the Man of Steel.
Even if Zod doesn't make it out, he can send Superboy through as a double agent. This was foreshadowed when Superboy hallucinated snapping Kal-El's neck, akin to Henry Cavill's Superman killing Zod in the DC Extended Universe. This would send shock waves through the galaxy, because Superman has been crucial on peacekeeping missions, with many adoring his diplomacy. More so, it'd take Conner's brother away from him and damage the El legacy.
However, it's not just Superman, but the World's Finest under threat. Conner also hallucinated breaking Batman's back, just like Bane in Knightfall. Given The Dark Knight always had contingency plans in case a Kryptonian went bad, it's easy to see him rushing to fight an evil Conner and losing. With the Bat being a key Justice League member, it'll be a major loss for Earth and the cosmos, tarnishing Superboy's reputation forever.
Since the Zone is a unique pocket of space and time, these kills may be premonitions masked as bad dreams. As such, Conner may not have a clue he's walking an inescapable path of regret, with the House of Zod possibly prepping to use him as the ultimate revenge pawn. Ultimately, it'll shift Conner from guarding the cosmos, to leaving it vulnerable to the Zods, Vandal Savage's sinister army, as well as Darkseid's family.
New episodes of Young Justice: Phantoms debut every Thursday on HBO Max.