Three Kingdoms: Sworn Brothers with Lü Bu

A modern otaku travels back to the chaotic end of Han dynasty, and immediately runs into the Bingzhou army. Captured as a spy by Lü Bu's men, he uses his knowledge of the Three Kingdoms to survive. Knowing Lü Bu's unmatched bravery but foolishness, he becomes his strategist, changing his fate. From a close advisor to a sworn brother, he teaches Lü Bu patience, strategy, and leadership, turning him from a notorious turncoat into a dominant emperor. Together, they defeat Yuan Shao, Cao Cao, Liu Bei, and conquer the world.