Apocalypse+System+Semi-invincible+No heroine+No harem
Gu Han, the top modern killer, travels through the doomsday wasteland with his mysterious system.
Alien beasts are rampant on the surface of the earth, while humans are barely surviving below the ground; he proves his way through killing,
From being a prisoner underground, he fought his way back to the surface step by step, until he became the strongest master of this universe.
