The Ace Undercover of Southern Song

The story is set in the sixteenth year of the Jiading era during the Southern Song dynasty. Shen Mo, a modern undercover detective travelling to the past, begins his ambition to manipulate and bend the empire to his will. Armed with countless schemings and trickery, he uses his modern detective skills to crack many strange cases in Southern Song, as well as his mastery in espionage to torment the secret agents from the kingdoms of Liao and Jin. And when the threatening conquests of the invincible Mongolian cavalry begin to draw near, he trains an army made of steel to smash their sweeping invasion! To single-handedly dominate the world and fight against the odds, this is the epic war of a man versus an era!

(Source: Bilibili Comics)