The once glorious modern civilization collapsed in a global disaster, and the world became a horrific apocalyptic wasteland. This disaster was caused by the leakage of a mysterious virus. It not only mutated a large number of humans into terrifying monsters, but also destroyed most of the infrastructure and technological systems, plunging human society into chaos and despair. The entire earth is occupied by ruins, radiation zones and monster lairs, and the remaining humans struggle to survive in this harsh environment.
