Lin Yuan, a time traveler, is bound by an absolute contract called "Civilization Survival".
The system asked him to patrol the darkest moments of China's five thousand years and watch alone on the edge of the cliff where civilization was about to die out.
[Fei Shuangwen], [Not brainless] [Through the history of the heavens]
[Not magic modification], [No harem], [High readability], [Regret], [IQ online]
