Leo time-travels to Great Qian and unexpectedly meets Grace, the Grand Princess, after she has been drugged. With the Emperor gravely ill, Grace's uncle Rex pushes for a marriage alliance with the Northland. To protect herself and the court, Grace takes Leo as her prince consort and sends him to the Six Gates Bureau as a trainee constable. On their wedding night, Leo activates the Empress Support System and quickly grows stronger. He captures a Northland spy, makes his name in the capital, and meets Mandy, a noblewoman who commands the Imperial Guards in North City. Later, Leo uncovers Prime Minister Ryan's treason, exposes his corruption through a public wager, and brings him down, earning the title of Lord Defender. Afterwards, Leo foils the Northland's marriage scheme, leads the Vanguard to crush Rex's rebellion, and is named Supreme Commander. After breaking through to the Demigod Realm, he defeats the Northland army with Blade Tempest, helps Grace ascend the throne, and is finally named Prince Regent. In the end, he gains both love and power.