The Blacksmith's Genius Son-in-Law

When a modern materials engineer wakes up in the past as a penniless scholar, a blacksmith's daughter buys him for three silver coins to become her husband. Mocked and targeted by a ruthless local tyrant, he uses his advanced metallurgical knowledge to revolutionize the forge, crushing rival master smiths and corrupt elites. Appointed an imperial weapons master, his newfound glory is shattered when northern barbarians invade. Can his cutting-edge steel save the empire from destruction?