The Sleeping Duke's Bride

"A mistreated young woman proposes a marriage of convenience to a cursed immortal duke to protect the only home she has ever known."

After losing her parents as a child, Kalendia is adopted by Count Gies’s family, where she spends her days enduring abuse. One day, she is forced to marry in her adoptive sister’s place to an old duke who lives in isolation in the mountains.
However, upon arriving at the duke’s residence, she finds not an elderly man, but a young man with a melancholic appearance. Even more surprising, there is a dagger lodged in his abdomen. The duke reveals that he bears a curse of immortality and begs Kalendia—the only person capable of seeing the blade—to remove it. The problem is that if she does so, he will die. To protect the first place she could call home, Kalendia proposes a marriage of convenience to the mysterious duke.

Original Webtoon:
LINE Manga, eBookJapan, MechaComic

Official Translations:
B.Portuguese