They Traveled Through Time, and I Was Responsible for Correcting History.

I have the ability to travel through history again and again. But my job is not to change history. Instead, find those steam engines, muskets, potatoes, modern military systems, democratic systems, and the industrial revolution that appeared in advance... Then find the travelers behind them. Restore everything to the way it was meant to be. Until one day, I traveled to 221 BC. The system tells me: "Warning: Historical anomaly detected." "Abnormal target: Qin Shi Huang Ying Zheng." "Suspected time traveler." And I suddenly realized a problem. If even Qin Shihuang was a time traveler... So whose history is it that I have been defending?