After transmigrating, the heroine wakes up to discover that she has been betrothed to the God of War of the Northern Frontier, Prince Zhenbei Xiao Xuanye.
Xiao Xuanye commands three thousand personal guards, the Black Armor Army, but his achievements have made the court fear that he will grow too powerful. The three thousand men are trapped in a lonely, isolated city.
Using her modern knowledge of history and military theory, the heroine transforms these three thousand men from expendable pawns into an iron wall that shields the land.
The heart of “three thousand protecting all” is this: the three thousand men protect not just a city, but all the people of the Northern Frontier, as well as the heroine herself and her shattered fate.
