I Have No Magic Power, but the Marquis Dotes on Me

In a world where everyone, young and old, man and woman, possesses magical powers, Charlotte alone was born without any at all. When she comes up for auction, this unprecedented trait repels all potential buyers, and she is left for dead. Suddenly, a nobleman named Arthur appears, offering to take Charlotte for thirty million. Arthur, who has declared himself Charlotte's guardian, fell in love with her at first sight. He then proposes marriage, explaining that her body, devoid of magic, holds the key to saving him from the torment of excessive magic in his own. Though bewildered by Arthur's sweet demeanor, Charlotte hopes to carve a place for herself in the world. But to save Arthur, a certain act is necessary...!

Original Webtoon

Official English:
Coolmic, MangaPlaza