They Are All Time Travellers. I Started by Picking up Shit.

When he woke up, Lin Fan found that he had become a domestic slave of the Zhou family in Blackstone Town in another world. His daily job was to pick up feces? Living at the bottom of society, suffering from hunger and cold, prone to disaster, the future is gloomy. In a desperate situation, a system called [All Things Return to Ruins] quietly awakens. The starting ability is to recycle waste? Cow dung, scraps, broken copper and iron can all be turned into tiny amounts of energy, which can strengthen one's body and even unlock storage space. With this inconspicuous ability, Lin Fan was able to carve out a glimmer of light in despair. He collects excrement to accumulate energy, hides coins, and carefully hoards the hope of freedom like a hamster. However, the system is capable of much more than that. When he accidentally recovered the dead spiritual roots and recovered from his injuries, he was shocked to realize that there seemed to be a deeper secret behind this "waste utilization". Until one day, he passed by a desperate suicide, and the system prompted an icy sound: "Ding! Special waste detected: Lifespan, do you want to recycle it?" Is it to take advantage of people's danger to seize life, or to stick to the bottom line and miss opportunities? On the road to immortality, among the endless recycling, what kind of existence will he eventually become?