Traveling Through Chang'an in the Qin Dynasty, I Helped the First Emperor Settle the Nine Provinces

The modern person is Ying Chengyu, the son of Qin State, who grew up with his elder brother Ying Zheng. From the years of prostitution to the unification of the six countries, the two brothers walked side by side. With his modern knowledge and strategic vision, he assisted Yingzheng to eliminate civil strife, unify the world, rewrite the fate of Chang'an Lord, and jointly create an unprecedented prosperous age of the Qin Dynasty. (There is a private setting, if you mind, it can be protected from lightning)