The Mermaids Curse

Ella West was just four years old When she drowned in the ocean and was saved by a merman who provided her with protection and a home. The only way that he could save her was to turn her into a mermaid and since it's illegal to transform a human into a mermaid or a merman he had to keep her hidden for the transformation. Now she's eighteen and guards the territory. There's just one problem, she kills every sailor that she sees...if he's underwater. But one day she sees a sailor and instead of wanting to kill him, she wanted to save him. So she does that only to find out that he knew here while she was human. Does that mean there's hope for her to become a human again and walk the earth? Or is it a message that she should change him into a merman?