Grace

Grace is seen as the twin "sister" of the slime girl Moira. But where her morals lie are completely bipolar to her sister's. Mainly in the area of breeding and merging with humans. She finds intense thrill of tainting the reproductive systems of them and is generally seen as a bit of a harlot (putting it nicely).

As per her relationship with her sister, they do not get along and avoid each other at all times. But unbeknownst to Moira, Grace has the chunk of her missing memories and experiences within. She knows it, and it intentionally keeping it from her.