The witch hunter of the last days

Heaven and earth suddenly changed, the demon race invaded, and the creatures mutated. Humans instantly fell from the top of the food chain, and in the blink of an eye, even became the lowest existence, becoming the food of all mutated creatures.　　 However, just when the earth is about to be destroyed, Zhang Mo, a mercenary who accidentally obtained the Demon Hunting System, becomes the only savior of mankind and the only chance for mankind to save its own destiny.　　 Famous historical generals who had disappeared in the long stream of time reappeared with their own exclusive teams in Zhang Mo's creative ability to kill the demons