Xiaoyaoyou: the Great Demon Country Grass Record

Chen Shen, a high school boy who reincarnated into the world, contracted a strange disease. In order to repair his dream, he had to use the four-dimensional space to find memory fragments in his past life... Time travel caused Chen Shen to lose his memory of the current world. His predecessor was Prince Nan Chen. Although he was still alive, his country was destroyed. With his growing military and political talents, he, the prince of the subjugated country, wrote his wonderful life in the turbulent era of the Sui and Tang Dynasties... Life is like a grand tour.