Pelleas
Pelleas is a fictional character from King Arthur-related legend. He was a Knight of the Round Table . Pelleas deeply loved Ettard. She was a young unmarried woman  who did not love him in return. The knight Gawain offered to try and convince her to love Pelleas, Gawain betrayed him and slept with her himself. Intigued by the situation, Nimue used magic to make Pelleas fall in love with her. She also made Ettard fall in love with Pelleas. Since he did not love Ettard anymore and she now desperately loved him, she died.