Travel Through the Three Kingdoms and Help Cao Cao Conquer Thousands of Armies

The protagonist traveled through time, saved Cao Cao from danger, initially showed his value, gained trust, and began to test his skills in the military and agricultural fields, conquering the first elite army. Help Cao Cao unify the north, systematically introduce modern knowledge, comprehensively upgrade military equipment, industrial production, medical and health, and intelligence systems, and establish an absolute advantage over the princes. Sweeping away Liu Bei and Sun Quan, establishing the Wei Dynasty, eradicating internal hidden dangers (Sima family), and bringing the protagonist's acquaintance with Cao Cao to a successful conclusion, and the protagonist retires with success.