The Ruler Of Darkness

His cover was made of the skin of those who hold a grudge against humans. His words were written with the blood of those who hold a grudge against heaven. His weave was created from the sinews of those who hold a grudge against earth. The heavenly demon, the ruler of darkness. Yeon Sang-hyeon, who signed a contract with the ruler of darkness at the last moment of his days, is now rewriting his own destiny. The Heavenly genius met The Heavenly demon! — Description from novelcodex.org