Tang Luo, an ordinary courier living at the bottom of the city, has a cowardly and introverted personality, and does not dare to resist when being bullied. His only hobby is to put on a VR helmet and enter a Western fantasy online game called "God's Domain" before falling asleep late at night. There, he is the number one assassin "Night Stalker" who is feared by all players.
By accident, the "blackening system" in the game resonated with reality. Tang Luo discovered that as long as he killed monsters and completed tasks in the game, the "magic energy" and "dark skills" he obtained could be synchronized to the real world. From then on, he can enter the "demon" state with a single thought, possessing strength, speed and dark perception beyond ordinary people.
Just when he was about to use this power to change his life, a mysterious organization "Holy Light Judgment" came to his door. They claim that they are the guardians of the real world and specialize in hunting down "magic-infected people" who escape from the game world. What shocked Tang Luo even more was that the actions he was accused of in the game had led to many bizarre deaths in the real world.
Overnight, Tang Luo changed from victim to suspect. The pursuit by the Holy Light Judgment, the pursuit by the police, the betrayal of his colleagues, the manipulator of magical energy hidden in the dark... When the whole world regarded him as a monster, Tang Luo finally understood: Either he will be swallowed by this world, or he will completely fall into darkness and become a demon with one thought.
