The Heavenly Emperor of Darkness Manhwa

Once forsaken by the world, a child found themselves thrust into a world of darkness.
This unfortunate child had to survive in a horrifying place, surrounded by the agony of others, where people were torn apart, and screams filled the air.
However, fate took a surprising turn when a powerful demon mysteriously vanished from the secret prison cell within the imperial palace, a place from which no one had ever escaped.
Miraculously, this powerless child, who had lost everything, underwent a transformation. They emerged as the new emperor of darkness, gaining immense power and authority in their rebirth as the ruler of the shadows.

暗天帝, 암천제, The Celestial Emperor of Darkness