He Stole My Military Merit and My Fiancée. Now I’m a General, So Why Are You Panicking?

He transmigrates into an alternate world and becomes the legitimate eldest son of the Prince of Xiao's household. Before he can enjoy even half a day of comfort, his parents force him to take his younger brother's place and go to war. For three years, armed with his modern knowledge and extraordinary abilities, Xiao Ling slays enemies on the front lines and rises to become the General of Heavenly Strategy! Just as the army is on the verge of a great victory, a secret letter from the Prince of Xiao's household arrives out of nowhere. It demands that Xiao Ling hand over all the credit for his three years of service to his younger brother. Taking care of his brother was just a lie. The truth is, they wanted free labor! Facing his delusional parents, Xiao Ling only gives a cold laugh. “You want to steal the fruits of my labor?” “Sorry! With your status, you aren't qualified to give me orders!”