Returning to Ancient Times as a Tyrant

A modern university student transmigrates to the Great Qin Empire, where civil affairs are valued above military strength, and becomes the emperor. Faced with an enemy princess who bullies him and his own chancellor usurping power, he boldly promotes military generals and uses modern knowledge to build weapons. The northern cavalry are formidable? How about a taste of my machine guns and cannons! The Eastern Liao navy is powerful? Let's see how well my aircraft carrier handles being rammed! The Western Liang soldiers aren't afraid to die? Drag every last one of them off for human experiments!