The Carefree Sixth Prince

A modern young man transmigrates into the body of Liu Zehan, the Sixth Prince of the late Dakang Dynasty. Framed by the Crown Prince, he is sent to sign a humiliating treaty after a lost war, a plot to doom him. With two lifetimes of experience, Liu Shaoyi quickly analyzes the situation and debates the enemy, saving the empire 200 million taels of silver and reducing the ceded territory from three provinces to one. He then awakens a conscription system that equips his recruits with the world's most advanced armor, weapons, and supplies. From then on, his life is on easy mode! He punishes traitors at home, repels foreign enemies, expands the empire's borders, and is invincible. Ten years after his rebirth, he ascends the throne, only to find there is no land left to conquer—the seven continents and four oceans all fly the flag of Dakang! — Description from novelcodex.org