After the Substitute Daughter Goes on a Killing Spree

I'm writing this so badly. Everyone, please try not to read it (╥_╥)

The engineering genius Jiang Wan transmigrates into the body of a fake heiress with a stand-in marriage plot. Her husband is the Marquis of Dingbei, rumored to have been wounded on the battlefield.

She's also bound to a ridiculous System that requires her to improve people's livelihoods!

The new dynasty is still recovering from devastation, and the northern frontier is engulfed in war, with its people living in poverty.

Jiang Wan: Don't worry! Let me show you what a dimensionality-defying advantage looks like!

She builds workshops, reclaims farmland, develops firearms, improves water conservancy, and establishes schools... She vows to lead the people of the northern frontier to a better life.

From then on, the bitter, freezing northern frontier, once dotted with beacon towers, undergoes a complete transformation. The arrogant and brazen northern tribes are as meek as quails in the face of cannons and firearms. The people are prosperous and healthy, and women can establish their own households and shine in their own right...

With the northern frontier's defenses secure and its people prosperous, Jiang Wan has made invaluable contributions and is honored before the emperor. From then on, throughout the twenty-four offices of the six ministries of Great Sheng, everyone respectfully addresses her as "Lord Jiang."

Theme: Improve people's lives and welfare, and be self-reliant and strong