A Mysterious Express Delivery Across the Tang Dynasty Every Week

Traveling back to the end of the Sui Dynasty and the beginning of the Tang Dynasty, I saw with my own eyes the end of Yang Guang and the establishment of the Li and Tang dynasties. I was there when the Xuanwu Gate was opened. I am the Poet Immortal King Taibai, I am the miracle doctor, and I am also the president of the First Academy of Sciences of the Tang Dynasty! Relying on weekly express delivery, I changed the Tang Dynasty!