Datang: the Prince of Xuanwu Sect Didn't Do the Right Thing in the Beginning.

I wanted to live a prosperous life as Prince Taiping! Why are there always bastards who force themselves to perform meritorious deeds! Li Yu was originally a salesperson for a medicinal company in the 21st century. He accidentally traveled to the Wude early Tang Dynasty in the parallel world, and became a disciple of Sun Simiao. At this time, the founder of the Tang Dynasty, Li Yuan, had chosen "Zhou" as the country's name when the country was founded, and Li Xuanba, who died early in history, actually became his father. Making salt? Making ice? Gunpowder? The collision of cold weapons and modern technology? Grassland? Turks? Tuyuhun? Taking the Tang cavalry to the plateau? Facing an unknown future and a slightly different historical process, Li Yu, who had just escaped from the Qinling Mountains through all kinds of hardships, was forced to accompany Li Er to confront the princelings at Xuanwu Gate...