Return to the Tang Dynasty and Become the Grandson of the Emperor

Traveling back to the late Kaiyuan years of the Tang Dynasty, the emperor neglected government affairs, treacherous ministers were in power, and there were wars on the border. As the emperor's eldest grandson, I must stand up. Defeat Li Longji, fight Li Linfu, punish Yang Guifei, kill Yang Guozhong, kill An Lushan, and stop the Anshi Rebellion in advance. I want the prosperous age of the Tang Dynasty to never end. I want the sun and the moon to shine, and the wind and rain to be the land of the Tang Dynasty!