A woman stood atop a roof, gazing at the world below.
Her name was Lilith. She was not what she seemed. Anyone looking at her would have seen a slender young woman with black hair and dark eyes. Her skin was almost bone-white. She was a lot more than she appeared.
Lilith was immortal. She was the First Woman. Created by the Almighty Himself to be Adam's wife. Lilith rebelled against God. She defied the will of the Divine. She was cast out of Paradise long before the creation of Eve, which led to Man's downfall. Adam and Eve were the first Man and the first Woman. The Heirs of the Almighty. Since the original sin, they became mortal and when their time came, they died. So it has been for all humans since the beginning of time.
Not Lilith.
Since she was cast out of Paradise before humanity became mortal, she remained immortal. She was not human, though. Lilith had dealings with the enemies of God. Her lover was none other than Lucifer himself. Lucifer was the leader of the Fallen Angels. The dark angel who led an army of rebel angels against the forces of Light. Lucifer and Lilith had children. These children were half human and half demon. They became collectively known as the Demons.
One day, God decreed that the Earth would no longer be home to the demons. He sent a Deluge and wiped out the monsters, along with many elements of Creation. Still, Lilith and her children survived. They continued to breed for thousands of years. Lilith was the Mother of the Race of Demons. All demons are in one way or another descended from her. She had many children by many lovers. She had sexual relationships with humans as well as demons and fallen angels. The offspring that came from her were born immortal and sworn to darkness.
The Deluge came and wiped out most of life upon the earthly plane.