In theory I don't try to read one genre exclusively because a good story is a good story... In practice however I find myself reading Fantasy and (more recently) Sci-fi again and again. I read for fun and to entertain myself.
So. This book. Hm.
I think objectively it's not a bad book, but I hated it. Okay, no, hate is too strong a word. It's just that while reading Empire of Thorns I didn't have one single positive thought, which not a lot of books have managed so far, I can tell you that.
I keep wondering what I liked about Prince of Thorns, because it must have been at least somewhat entertaining or I wouldn't have given it three stars. Yet I don't remember.
Anyway, onto the reasons why I didn't like the book.
Let me start with Jorg from which point of view most of the novel is written. First person narrative is always tricky because if I don't like the character it kind of ruins the book for me. Jorg is a bit of a mixed bag. Often he's a villain, sometimes he's not and actually shows he cares about (a very few) other people. Sometimes he's mature, often he acts like a little child from whom you've taken its favorite toy. He has daddy issues and he wants to be emperor because someone told him he couldn't be one. He's not a compelling character. You know, for me, the best kind of villains are subtle, cunning and capable and present a challenge for the heroes. They're even better if they are the kind of characters who just see the world in a different way, but aren't necessarily wrong, because the world isn't black and white. Jorg isn't that kind of character. He's the kind of dumb villain that just wants to see the world burn if things don't go his way. Nope, Jorg did NOT work for me.
The other characters aren't much better. They weren't really fleshed out and Katherine was borderline offensive with the way she kinda was interested in Jorg while believing he had raped her. WTF!? And when certain people started dying I simply did not care. In fact the only time I was bothered by someone dying was the incident with the dog. That should tell you all you need to know.
There is a lot of jumping between timelines that was so annoying because it felt more like a gimmick than necessary. We have two main timelines - the "present" when Jorg is 18 and the "past" where Jorg is 14. Sometimes Jorg would remember stuff from before the past when he was little child or from before the present but after the past. Then there were also Katherine's diary pages which Jorg actually discovers at the very end of the novel but which narrate what's happened to her in the last four years.
Obviously the reason for the time jumps was so Jorg could explain what had happened in the past to make events in the present possible. Except that one time where Jorg is like "so I got this thing but I'm not going to tell you how I got this thing because that's a story for another time muhahaha". I don't know what *that* was about. Maybe the author hit his word limit or whatever.
The plot was so underwhelming. So the present is all about fighting an army that's ten times the size (or was it even twenty?) of Jorg's army. As mentioned the past explains how Jorg is able to do so and comprises mainly of Jorg travelling from point A to point B to point C. That's basically it.
What was even more underwhelming was the worldbuilding. This is a fantasy novel, so I expect the development of an imaginary setting that's interesting and compelling and somewhat unique. This? This was the most lazy worlbuilding I've ever seen.
The setting is supposed to be 1000 years into the future after mankind fucked up and almost destroyed itself. Everyone has forgotten the good old times and not a single person in one thousand years has shown inventive talent. So everyone's stuck in the Middle Ages which are - and here comes the lazy part - almost exactly like the original Middle Ages including medieval terms that no one in our time has been using for centuries but are somehow revived 1000 years from now. So we have once again vikings, jarls and moors.
The funniest part is where the author actually explains why no one in one thousand years has made any technological progress because he must have realized what bullshit that is. So he has his animus ex machina tell us:
"There's a gap between what I say and what you can comprend. You people could fill that gap in fifty years if you stopped trying to kill each other and started to look at what's lying around you."
The world also felt strangely empty. Not just of people, but also culture. We meet Danes whose defining traits seem to be having beards and carrying axes instead of swords.
To summarize: Characters, plot and worldbuilding sucked. For me, anyway.