Yeo-wa

A crude-mannered woman sacrificed to Habaek as a bride and is rescued by Mui only at Soah's request, Yeo-wa schemes to get rid of Soah and take Habaek for herself. It was originally intended that she, not Soah, was to be sacrificed to Habaek; when she is sacrificed later, the Emperor gave her Nakbin's appearance to use her against Habaek. However, she genuinely falls in love with Habaek and begins to think she is truly Nakbin, but is eventually killed when she outlives her usefulness. (Source: Wikipedia)