Desolate Devouring Art - Chapter 174 - Underground Palace

Xia Yuqing is a shut-in+fujoshi from the 21st century. After an accident, she transmigrates into the body of a young princess forced into a political marriage to another country.

Summoning ceremonies can freely call forth even “those which lurk in the depths beyond the gods”. One boy has top-level abilities even among the cutting-edge summoners who can use those ceremonies. He is Alice (with) Rabbit aka Shiroyama Kyousuke. But this strongest boy summoner has a single fatal weakness. Certain “cursed words” spoken by girls: “Help me.”

When Kyousuke hears those words from Meinokawa Higan, a girl brought to the verge of death, he throws himself into a city where three great summoner forces clash!

This novel is also known as Long Live the Mad Wife!

Daughter of the Feng Family, born a waste. Forced to marry a fool in an attempt to expel evil influences. When the first killer from the 21st century possessed this body, the sky and the earth surged. She was indifferent and cold-hearted but she let her guard down around him alone. She thought he was a pleasant sheep but didn’t expect him to be a gray wolf in disguise!

- Description from Novelupdates

She was forced by her husband and his mistress to jump into the sea and commit suicide, only to be rescued and taken care of by the jerk's uncle for seven years.