[Historical hegemony + One Emperor through the ages + Dimensionality reduction attack + Slow-heating infrastructure + Not the Holy Mother]
Chen Xing traveled through the troubled times of the late Tang Dynasty with a micro-technology library. When he opened his eyes, there were two energetic young men of 18 years old lying next to him - the reborn Qin Shihuang Ying Zheng and Han Wu Emperor Liu Che!
The lives of the three are bound and cannot hurt each other, and Chen Xing has absolute dominance.
At the end of the Huangchao Uprising, white bones were exposed in the wild, and there were no roosters crowing for thousands of miles. Facing the troubled times where the princes were separatist and cruel, Ying Zheng snorted coldly: "Give me three thousand cavalry, and I can pacify the Central Plains in half a year!"
Liu Che drew his sword: "Those who invade our territory will be punished no matter how far away they are. I will establish the strongest centralized power!"