This is the middle book of the Obsidian trilogy, so maybe it's a little unfair to review it, but it will be a good while before Dragon Venom comes out in paper. It's also been a good while since I read Dragon Weather, but I still felt like I wouldn't have understood what was going on in this one if I hadn't read the first one.
I'm not finding too much to say about this book, without just telling the plot. The writing was OK, but the story didn't really engage. The first book gave us an interesting concept of what dragons are and how they live, but the second one didn't do much more than re-hash it. Arlian, whose character is defined in the first book by his intense desire for revenge, becomes much more wishy-washy. He reconciles himself to his former human enemies, and when new humans betray him, he seems strangely indifferent. Other characters' basic natures seem to become weather-vanes, pointing where the plot is blowing.
This sounds like I really hated the book, but I didn't. I was disappointed, but I did get some enjoyment out of it, and I probably still will read Dragon Venom.
I'll give it a 6 out of 10, noting that if I hadn't come in with some positive feelings -- momentum, if you will -- from Dragon Weather, I would probably rate it lower.