Record of Chang'an's Shocking Changes: Eight Hundred Years of the Prosperity of Tang Dynasty by Zuo

I am Li Yu, the eldest son of Tang Zhaozong, the unlucky king who was hanged by Zhu Wen in Jiuquchi in history books. But that was the original script. Now I have a soul from eleven hundred years in the future. I have read "Old Book of Tang", "New Book of Tang" and "Zi Zhi Tong Jian", and I can recite the birth and death dates, character weaknesses and final outcome of each feudal governor. Liu Jishu wants to make me a puppet? I made his head fall to the ground. Zhu Wen wants to kill me in Jiuquchi? I left him blood splattered on the spot. They thought I was destined. They didn't know that I was just a candidate who had read the answers in advance. Eighty thousand divine troops, nine-level military rank system, repeating crossbows, plate armor, counterweighted trebuchets, military academy - I turned every bit of knowledge I brought from modern times into a dimensionality reduction attack in this era. Some people say that I am decisive in killing and that I am the reincarnation of Emperor Taizong. Some people say that I am cold-blooded and ruthless, unlike a sixteen-year-old boy. They're both right. No one can clean up this mess except me.