Origin story 2: Corruption
(I know I said that you'll see the next chapter in a few days but I wanted to do this before I forget to do it, plus this will hopefully help connect the Original's story with Absalom, Corruption, Charred council and Doomsday.)
The chaos and destruction that the Nephilim had brought to the many worlds they conquered had given birth to the Original Corruption which by the time Eden was under seige had the power to resist Holy magic, but was not immune. The Original lived within all the Nephilim, and when they were wiped out from existence the first Npehilim, Absalom was the only one to absorb his race's corruption.
But most of the Corruption was too much for the eldest Nephilim and thus created a copy that could place Absalom in it's influence, but it backfired as Absalom actually gained the trust of it's copy. Foiled in it's plans to control Absalom the Original that swallowed him in Eden hid in the bodies of fallen as Eden was cast in it's own realm away from Demons but never far from a evil influence.
The Original adapted to Eden's holy atmosphere but was weakened when near the tree of knowledge, in time though the Original gain enough resistance to head into the tree and learned the secrets to travel through dimensions and space. The Original used the knowledge it gained from the tree but because it was deemed unworthy to the Tree the Original was severely weakened with only a slime creature to move on.
The original made it's way to the Home world of the Raviim, the Prehistoric Krypton and was in luck as the young Doomsday was nearby and corrupted his soul. The Original laid dormant within Doomsday using him to fuel his power by going to worlds with corrupt souls it's power grew greatly while dormant but it wasn't able to reawaken until it sensed it's copy.
Corruption copy which chose Absalom as it's Avatar of chaos was less vile than it's Original, the copy's goal was the same but it did so under Absalom's instructions it's power invaded many worlds and nearly destroyed some. Until Death had killed Absalom and stopped the copy who formed itself a new disgusting body that could not corrupt the well without a chosen avatar.
Over the hundreds of years that Death slumbered the copy waited until it would be free, but unknown to him a plan was made to open what remains of the Earth's tree of life and release the copy. This drew out Death from his slumber for he was the only known being to resist the corruption's influence, there are other forms of corruption that were never told as well.
When the four horsemen who betrayed their kind they were purified by the Charred Council who extracted the corruption from the souls of the four, though the Charred Council thought to destroy the corruption they were instead consumed by it's hate they became the corruption they fought against which the four had to destroy. The Charred council were always thought to be corrupt before they were consumed, most even thought they lied when they stated that the Creator himself charged them by preserving the Balance, but they were only pawns to the will Corruption.