Geu Daegongui Hwaryeohan Gyeolhoneun Sagi

After a former art student wakes up as an art mage in the world of a novel, she realizes that she's now villainess no. 4, Shaye — and she's about to be sold at a slave auction! Luckily, Archduke Lacius de Schubeiden saves her, but for his own reasons. Lacius plans to generously pay Shaye to pose as his jealous wife so that his stalkers will stay away from him. And even though Shaye readily accepts his offer, it's anyone's guess as to whether or not they can pull off this fake marriage.

(Source: Tapas)