The “Bane” of Superman is none other than Doomsday, a monster that’s artificially created in the past on Krypton before the humanoid (kryptonian) race gained dominance over the planet. During that time, Krypton was a hellish world where only the absolute strongest of creatures could survive. Bertron wished to create the ultimate life form. To do so, he&his team sent a baby onto the surface where it’d be instantly killed by the harsh environment or the vicious creatures inhabiting it. Each time, whatever survived were harvested&used again, to create a stronger version than the previous. In short, the mad scientist was using the method of cloning to accelerate the evolution of the being he was creating. Through decades of this process, Doomsday was forced to endure the agony of death thousands of times; the memory of these occurrences was recorded in his genes&drove it to hate all life. Doomsday gained the ability to evolve against what killed him in the prior life without the need of Bertron’s tech&proceeded to hunt to kill all the lethal creatures that inhabited Krypton. Hundreds of Green Lanterns were sent to stop the killing machine but were killed. On Oa, a single Guardian sacrificed himself to defeat him. With Doomsday dead, the Guardians turned their attention to rebuilding the Corps. In reality, the release of massive energies by the Guardian caused a tear in space through which an unconscious Doomsday fell.
Doomsday, by Marco Nelor.