I recommend the novel "Great Tang Divine Military Advisor" to you. Although the main character, Li Yan, did not cross over to the Tang Dynasty because he accidentally killed someone, he also experienced many twists and turns and was forced to embark on the path of assisting the Tang Dynasty. This book was written by the author Piao Yi. It was a historical novel about the two Jin Dynasties and the Sui and Tang Dynasties. The plot was very exciting. I hope you like my recommendation, Mwah~