To the Flawless Duke

Edith—who lost her mother at the hands of the Reynolds marquis family—was branded a madwoman. She dreams of vengeance, but a chance comes to the powerless: marriage to the third prince, Duke Myers, who is rumored to be perfect in every way.

It's a marriage of convenience meant to use one another, and that's fine. If I can make you live through hell without even knowing it's hell, I will do whatever it takes. Keep smiling, Reynolds. Until I have paved the road to the very fires of hell right before you.

(Source: Naver, translated)