ミレス

A knight who awoke in the woods with no memories. Having lost all her memories, she named herself 'Milles,' which means 'nameless' in this world. She carries a deep darkness in her eyes. Because she has lost her memories, her original personality is unknown. Milles as she is now has a gentle, straightforward personality. When the darkness she carries is awakened, along with her memories, even greater darkness will be called forth. After masturbating at a shrine of the local god, Milles regains her memories. It turns out that Milles was a servant of Diva-Sama. And that she used to be a slime monster who was given a humanoid body. This is because since Milles (when she was a slime) wanted to become the sacrifice for the year, Diva did not understand her feelings, so he gave her the form of a beautiful woman; a tribute to the beautiful girls that got sacrificed years prior. [From MangaGamer]