The Heavenly Emperor of Darkness is a Manga/Manhwa/Manhua in english language, Action series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.cc fastest updating comic site. The Summary is

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.