Usurper Hero? No, I'm Just a Mere Imperial Regent

The hero who defeated the Demon King volunteers to become a border lord. Using knowledge from before he transmigrated, he builds up his power step by step and takes control of the empire through sheer force.

Princess: “This is treason!”

Luo Wen: “Your Majesty, I’m merely purging the court of those who would lead you astray.”

Noble: “This man has no chivalry.”

Luo Wen: “I follow Daoist philosophy and believe in letting nature take its course. The Dao is ballistics, and guns are the art of marksmanship.”