MTL - Wonderful Life After Exchanging Fate - Chapter 129

Coming from the modern era, she was sent to a strange world. The body she possessed previously belonged to a young woman whose family was thrown away by their clan. However with the “Dan Fu Zong”, the inheritance from her old world, she steps on the path of cultivation, hoping to one day become an immortal.

- Description from Novelupdates

Su Wen transmigrated and became the Prime Minister’s son, possessing both power and money.

Transmigrating into a world of cultivation, you find yourself at the lowest rung of the sect's hierarchy. Everyone wants to bully you to gain some benefits. Fortunately, there are always a few junior brothers and sisters who are 'generous and understanding', allowing you to improve peacefully and secretly grow stronger. Years later, unbeknownst to anyone, you successfully become a deity within the sect. This day, your master visits you at the sect's request.'The upper echelons of the sect believe you have been diligent and loyal over the years, and though your strength is mediocre, you are an honest person, so they've found a marriage alliance for you.''An alliance marriage?''Not exactly. The other family has a rule: marrying into their family means taking their surname.'Is this... becoming a son-in-law who marries into the wife's family?