Qin Yun, the disgraced crown prince banished to Northern Liang, rises against all odds with the help of a sign-in system. He acts swiftly and decisively to eliminate local tyrants, opens granaries to distribute food and win the people's hearts, suppresses bandits, and renovates the city, revitalizing the impoverished border town. Through the system, he acquires the Black-Armored Iron Cavalry and Champion Marquis Huo Qubing, while the divine general Zhao Zilong deploys a network of secret agents across the realm. When a million-strong barbarian army breaks through the border and marches south, Qin Yun leads five thousand cavalry to crush its two-hundred-thousand-strong vanguard and launches a nighttime raid to burn its provisions. With an iron-fisted resolve, he guards the frontier and stirs up turmoil across the realm.