Magicless Bride, Powerful Rise

Evelyn is born into a noble house in a world where magic decides everything, and she is born without a mark. The law says the Markless are put to death. Her family passes her off into a marriage with Lucian, who everyone calls a monster, and the match is treated as a way to be rid of her rather than a match at all. She lives with him expecting to be handed over or worse. Lucian protects her instead. Her magic wakes while she is under his roof. The two of them go back through the death of her mother and find that it was murder, and the trail runs into the same bloodline law that condemned her. Evelyn breaks the rule that has stood for centuries, and Lucian stays with her through it.