The Hunger He Brought Back

Synopsis

Si Chen died as the last man standing, an SSS-rank lightning assassin who burned his own soul to take a demon king down with him. He opens his eyes in the infirmary of the National Awakener University, ten years in the past, with a system window only he can see and a sister who is still alive. Three years from now the first demon king will descend and force the gates of hell open. But in this era the guilds own every demon lair, a student at the bottom of the food chain has nothing to hunt, and the thing integrating inside him has started to wake.