The Sea Witch: A Little Mermaid Retelling

When Averil saves a young man from a shipwreck, she thinks she feels the Soul Echo--the sign that the young human male is her one true mate. And the malevolent Sea Witch is all too happy to offer a deal that could make all her dreams come true. He wants her to win the prince's heart--even coaches her in the art of seduction. But what is the real price of the Sea Witch's help? Why is he more brutally beautiful--and charming--than Averil expected? [TW/CW: age gap between fantasy characters, violence, abu-se, tort-ure, murder, se-x-ual threat, self-harm, expl-cit intimacy/spicy scenes, inexperienced/vir-gin female main character]