I should have noticed that maybe it's a bad idea to put an actual genocide (as in, one that has actually happened in history) inside a fantasy novel, for no actual reason. I mean, this book did not try to do any work with the historic material. It's just a setting for the plot. There are more problematic things which I didn't notice at all, I will just link the reviews.
www.goodreads.com/review/show/2502373487 www.goodreads.com/review/show/3734030651