This book wasn't spectacular but it wasn't terrible either. The book is about a mermaid who seduces princes and kings for revenge every year on her birthday. To kill a kingdom could've been much much longer but that's probably just a preference of mine since I don't ever want a book to end. This book has a nice enemies to lovers romance trope which I am very very fond of. I honestly hated the main female character in the beginning. I don't know why. She seemed a bit intense and blunt for my taste. You'll see what I mean once you start reading it. I did still like her character very much since she seemed like a strong female main character which is something I don't find that often. It is always good to find more strong female characters in books. This book was definitely a little mermaid retelling but more cruel and adult. If you have the time or feel like reading something quick but enjoyable then go for this.