I'm going to start by telling that a certain scene in book #2 totally disgusted me of the MC Tarod and of his romance with Cyllan. So, obviously, I found that everything related to romance in this book was irrealistic, especially since they don't know each other for that long. In the span of I'd say 2 months, they're ready to die for each other, which is dumb.
The think that actually earned this book 3 stars (because the romance was so bad that I cringed everytime Tarod and Cyllan were interacting or thinking about each other, which is about 3/4 of the story) was Yandros.
I think the author did a really good job with this character. He actually cares about Tarod (which is normal, since they're brothers) : he tries to tell him not to side with Aeoris, as it would only lead to his death.
An other thing I like about him was that he lived to his reputation. When Sashka killed Cyllan, I was hoping for Yandros to ressucitate her - because that's exactly what a chaos god who has life and death powers and who's in front of the dead girlfriend of the brother he just won a war with would do. I feel like a lot of other authors wouldn't have dared to do this, because they would have feared it would erase the feeling that there is consequences, but it's really what should have been done. I don't even like Cyllan or Tarod in the first place, but that's just logical. I can't say the same of Cyllan becoming a goddess, but I'll talk about it later.
And the author does also a good job of portraying who is Yandros : you can't forget he's a god, but he still has a small part of humanity.
About the other characters : I feel like Sashka realistically shouldn't hate Tarod (or be jealous of Cyllan) that much, as it is implied that she didn't really love him in the first place. That last scene where she killed Cyllan was maybe a bit too much (I mean, I would have understood if she just created a fight - but she KILLED her. (Nearly) no one kills the actual girlfriend of their ex, and Sashka didn't even love Tarod.
About Cyllan...I feel like she could have been a great character, but the only roles she had were "the lover" and "the chaos god workshipper". She could have been a paladin fighting for the chaos gods ? She would have been badass. But no, she was completely useless. And she was actually an obstacle for Tarod, as she couldn't go five minutes without being taken hostage. Not that he didn't deserve it.
I was already disgusted by Tarod in book #2, but I'm still disappointed that he didn't refrain from killing Sashka after she killed Cyllan. I was also disappointed when in book #1 he killed the guy who killed Themila. Each time, he couldn't control himself and killed people while those people were asking for his mercy. What does it teaches us about Tarod ?
Well, 1. He has terrible impulse control and 2. He isn't really better than the one he fights.
About the end (I told you I would be speaking about it) : I really liked the opposition before the final battle (if you read it, you know I can't really say anything about the battle) and how Yandros allowed Cyllan to live. But I can say that the fact that Cyllan became a goddess of Chaos totally ruins the story. Why ? Well,
1- We had no idea that Yandros, or anyone really, could turn humans into gods, and that power feels a bit too OP
2- The objective was to tell a story about balance : Light means nothing without darkness, and Order means nothing without Chaos. There is 7 gods of Order and 7 gods of Chaos - well, there were, because now there's suddenly 8 gods of Chaos, 7 brothers and one random girl who was a mortal before.
I know the author made this so the big romance does end good. But really, this makes no sense.
The writing style is still good, and the book would be really nice if book #2 wasn't what it is.