Xin Kai of the Wasteland

[Post-apocalyptic wasteland] [Urban] [Two-way transmigration] [System] Xin Kai is an overworked wage slave, and his unlucky mom opens the door for him to a wasteland in another world. He has a System, but he’s a complete pushover in combat, so he has no choice but to make his fortune scavenging battlefields. Gear? Scavenged! Food? Scavenged! Weapons? Scavenged! But the wasteland is full of traps, and Xin Kai gets taken advantage of at every turn. Greedy merchants! Sky-high rent! Shady agents! A gang that psychologically manipulates him! That is, until the saintly heroine finds him.