At the Worlds Mercy (spoilers)

Spoil the ending for me? This novel is really long, and I don’t want to invest my time or money into it if I end up disliking the ending or if there are too many dark elements in the romance. I’ve seen a few threads mentioning that the ending wasn’t great, but no one actually explains why, so I’m here asking for details lol.

I’m a fan of spoilers - I like knowing what I’m getting into before I start reading. So if you feel comfortable, please spoil the novel for me! You can share anything you think is important to know before reading.

Also, if there are any non con or sa elements involving the mc’s, I’d really appreciate a heads up.