18+ Sheathe Your Sword in the Bedroom

She was trained to kill. He was supposed to be the target. When assassin Yurian infiltrates the Argon Empire disguised as a princess bride, her mission is simple: murder Duke Larkan Blake on their wedding night and rescue her captive brother. But the notorious Duke is nothing like the monster she expected, and each night spent together makes it harder to carry out her revenge. Torn between duty and desire, will she choose love or vengeance?

(Source: Webtoon Entertainment)