Transmigrated Into The Joseon Era As The Powerful Demon King

[Warning: Mature content] Sunho is an average human who lives an averagely relaxing life, but one day after coming back from work, he confronts a group of gang members abducting a girl. He interrupts their mission as he occludes their devious schemes to save her, not realizing how dangerous they were and instead he falls into his death. The abductors put an end to him and he finds himself on the verge of death, the life fading from his eyes before the cloak of death finally wears on him. Sunho wakes up with a splitting headache only to find himself in an entirely foreign world, he soon realizes he's in the Joseon era but in a different body, he's in the body of a demon king. Bafflement and bewilderment strike him as he realizes another dimension of the world exists, a supernatural dimension in which his future as a demon King is unpredicted and obscure. He soon learns to cope with his new life as a demon King but when his demon starts to fight him to cave into his dark sides, will he be able to resist the tempting impulse of darkness or will he eventually surrender and become one with it?