The Invincible Mountain Bandit: A Million Troops and an Empress for a Wife

Qin Yu transmigrates into the body of a bandit chief and gets a Territory Expansion System to boot.

With the System, Qin Yu goes on a wild spree of recruiting troops, acquiring equipment, and developing technology.

Five years later, he runs into an empress traveling incognito, so he simply kidnaps her and makes her his wife.

Later, Qin Yu conquers the whole world.

Everyone tells Qin Yu he should be reasonable. Qin Yu replies, "I'm just a bandit. Why should I have to reason with you? Care to consider the ballistics?"