For example, in the first two books, Sullivan felt like a major character, and the whole romance plot felt significant. There was a lot of drama and tension getting those two together. Then FINALLY they get together and.... Sullivan disappears. He's just faded into the background. Technically they're together, but you'd never know it. He does NOTHING. He barely even says anything. And I'm fine with a book not having romance, but it's confusing to be led to think this is a "fantasy romance" in books one and two, then to have that "romance" part suddenly disappear in book three. I guess I just like a series to be consistent. Otherwise it feels disjointed.
I also feel like none of the other characters really developed. Some of them got there halfway, but never fully blossomed into anything significant. I guess that's because the main character has an issue with wanting to do EVERYTHING herself. That means she's the only one who does anything. She has a body guard who never guards her because the MC always gets attacked when she's completely alone, then kills the assassins by herself. It just feels like a wasted opportunity. The side characters are interesting, they just aren't given enough chance to fully develop.
Also this didn't feel like the conclusion to the series. I guess it still hasn't been solidified how long this series is meant to be, and given how long some of her other series are, it's entirely possible this one will continue to grow. However, I don't love going into a series not knowing how long it will be. You never know if the end is actually the end.
All that being said, this was still very enjoyable!