A Prince Sent to Marry? A Million Cavalry Ride South to Capture the Dragon!

[A prince sent to marry for peace + sign-in System + no suppressed cultivation levels or protagonist power + satisfying all the way through] Li Chengyou transmigrates in the morning, and by afternoon he learns he's being sent to the Turks to marry for peace. A prince sent to marry for peace? And he's the only prince left behind by the late emperor. Just perfect. He awakens the Sign-In System with ten-thousandfold critical rewards. From the start, he signs in at Zichen Hall and gets three thousand Invincible Guardians as a critical reward. He signs in at the Star-Picking Tower and gets the cultivation of an Earth Immortal. He signs in in Turkish territory and gets three thousand Iron Pagoda cavalry. Sign in... Li Chengyou arrives in Turkic territory in the morning. By afternoon, the Turkic Khagan has changed his surname to a Central Plains one. He calls Li Chengyou his dear son-in-law at every turn. When Li Chengyou unifies the grasslands with a million cavalry, the people there honor him as the “Heavenly Khagan.” A million cavalry ride south to capture the dragon. “You sent this prince to marry for peace. You were feeling pretty high and mighty!” “A million cavalry ride south to capture the dragon. Now your fate is sealed!”