Black Zero hails from an alternate time line where following Superman's battle with Doomsday, he never returned prompting Superboy to take up the mantle of Superman in his place, but unlike his younger counterpart he was not freed and reached his peak age. Black Zero continued in his role as Superman, however he constantly felt the public held a negative opinion of him for not being the original. This would come to be true as during a battle involving Supergirl, Maxima and Brainiac which ended in the deaths of those involved, causing the public to fear and hate Superman and all clones.
Following the death of Guardian at the hands of an anti-clone mob, he sought refuge in the Fortress of Solitude, where he learned of the Black Zero organization from Krypton, who sought to liberate the clones the Kryptonians used for medical purposes. Relating he took the name and set out to defend clones everywhere from oppression, declaring war with his army of clones which wiped out Earth's remaining heroes.
Following the conquering of his home world, Metron appears offering him the opportunity to "rescue" other worlds through the use of Hyper-Time.As he traversed dimensions he often attempted to have the Superboy's join him in his cause, but they all inevitably refused which led to them being stored in storage banks for further use. Eventually one Superboy escaped him through the use of the Hyper Jacket, where he died on New Earth to the surprised of Kon-El, who began traveling worlds with the jacket while being pursued by Black Zero.
Eventually Superboy and the countless other Superboys Black Zero had stored defeat the tyrant with the aid from the Challengers of the Unknown, with the Superboys returned home Superboy and the Challengers begin to pilot their ship home, but Black Zero eventually frees himself and during battle Superboy is lost from the the ship, only to be saved by Black Zero, who is then engulfed by a hyperstorm.
Powers and abilities
Tactile Telekinesis: A form-fitting telekinetic field that enables him to fly and deflect solid objects the instant they touch him, he can also extend the field to lift heavy objects, take things apart, and bend things into any shape he can picture mentally.
Pseudo-Kryptonian Powers: As a fully matured clone, Black Zero possesses powers, Superboy has yet to manifest, including the ability to project heat from his eyes ("heat vision") and ultra-acute hearing.
Like a true Kryptonian, Black Zero is vulnerable to Kryptonite radiation.