Late Ming Dynasty: Backstab Wu Sangui at the Beginning

I killed Wu Sangui and became the new master of Guan Ningjun. Facing Li Zicheng's million-strong army and Dorgon's 100,000 cavalry, I took out a magic book... To deceive the Shun army, plan to clear the troops, and seize the territory. While others are still struggling with loyalty to the emperor and patriotism, my goal is very clear: survive, and then, with 40,000 elite soldiers, conquer a huge empire!