I have some issues with the world building here that made it difficult to really immerse myself into the story. Those are my own though and had I taken the time to do some preemptive skimming prior to purchase rather than smirking at the mermaid angle and making sure it wasn't a three-some tale...
The h - Anne - is the great great granddaughter of Ariel. Yes; that Ariel. The spell that originally allowed Ariel to walk on land got twisted somehow when the seawitch attempted to remove it and her descendants have been cursed. At least one was a siren. None have lived past their 21st birthday - not because of disease either as Anne's mother killed herself.
The H - Jonah - is an angel who has lost his way...and in the beginning, his wing. Just one. The h finds the wing, hunts him down, and takes him to a safe place as per his directions.
The sea witch has a descendant too - Mina. Mina is also dark spawn - half dark one. She fights it and tries to help Anne.
It's an odd blend of fanciful fairy tale, sex that is often somewhat crude, and well, the emoting of an angel who needs to get over himself. He knows he's lost his way, and is reluctant to find it. Near the end, when the goddess tells him the origins of humans, he revolts. The h manages to heal his mind and heart, things happen, dark ones blow up, he mourns her passing (yes; she does die, but she wasn't supposed to, so gets a reprieve), has a good cry, and finds her again. The end.
Things I didn't like, odd world building or no - that finalish scene where she goes to a turned Jonah to try to bring him back to the light. It was so drawn out as to be ridiculous. She goes up to him, he punches her. She crawls back, he breaks her arm, she gets back up and tries again, he speaks in an evil voice that drives her down...again. She gets back up and tries to sing to him, upon which he punches her *again and this time kicks her. So she tries again. How I don't know. I was sort of wondering how she was still alive as she'd been hit twice by an angel. Anyway, he has his sword out with the tip resting on his hand - no, I don't know why a warrior of any sort would do that - and she climbs Mt Jonah again, kisses him, nearly cutting herself in half in the process, and while he's distracted, combines their blood for a bit of joining magic which finally gets his heart back in his chest where it belongs (it's in a jar, don't ask). Then she artfully dies.
His obfuscating and toe dragging. He's avoided the goddess for half a century. It's not clear why he stopped. The questions on how he got to this state in the first place. How was it none of the others noticed?
I'm sortof curious as to who the next one is about, but not sure I can sit through that much navel-gazing.