Gu Fang Bu Zi Shang - Volume 3, Chapter 63

Alzi had a promising future. At seventeen, the Goddesses blessed her with a life affinity—a rarity for commoners in a small village; a few days before the class-choosing ceremony, her Mother gets sick. After using her little mana to keep her alive, she runs to the capital to find a true healer. With no money, she sells herself into slavery for a decade. The decade is almost up, but she has been turned into a broodmare for the nobles and faces a sale to keep her enslavement going.

She was drugged by her ex-boyfriend and had her first night with a mysterious man.

This novel is also known as Master Fu's Mysterious Darling Wife

She is the The Young Miss of Military family Shen, her face is peerless, her temperament is cold, and she is her family’s treasure, but isn’t accepted as one’s child by her mother;

He is The Sole Heir to the top giant Fu Family, his power is unparalleled, indifferent high-born, the captain of the mysterious military force, and the youngest commander-in-chief.

Because of her grandmother’s wishes, she married him at lightning speed. She thought that it was a marriage that she needed, but she didn’t expect to be greeted with his extreme pampering.

- Description from Novelupdates

In a magical medieval world, it's difficult to hold on to one's beliefs... even maintaining one's integrity is a challenge.Because the commoners here are not simple; they are ignorant, greedy, and cruel.Because the nobles here are not noble; they are insidious, ruthless, and tyrannical.However... not all human constitutions can be generalized.Lann touches the two hearts and three lungs beneath his chest.He estimates that not only in this world but also in the other worlds connected through the convergence of celestial spheres, he can maintain a healthy sense of morality.—And then get rid of all the incorrigible scum!