Reborn in the Apocalypse, I Became the Heavenly Emperor

The apocalypse arrived, and Zhang Xiaosan inexplicably came back reborn, only to discover a white mark on his left palm and a black mark on his right. Monsters kept emerging from the fog-covered zones, overwhelming humanity with brutal force. Slaughter became the only way to fight them. The appearance of otherworldly spaces gave humanity the courage to resist the monsters, and eventually the confidence to face them on equal terms. They must not undergo the tribulation, or human civilization will collapse completely. Everyone who survives will have their intelligence diminished and return to primitive humanity!!!!