Shadow Kiss throws even more Strigoi at you than Frostbite did.
The whole link between Rose and Lissa is finally explained, which makes their relationship with each other even more fascinating to watch. It also explains a lot about some of Rose's past actions.
There's a lot more interaction between Rose and Christian, which leads to some amusing dialogue. The two are so similar, they're always loads of fun when they're forced together. It was also great to see the idea of Moroi fighting alongside dhampir being expanded on.
Eddy also becomes a main character, which he kind of deserves, especially after what happened in Frostbite.
The whole "ghosts aren't real!" thing coming from a bunch of vampires made me laugh. Perhaps more than it should have.
That ending, though...I did not see that coming. I mean, I knew something was going to happen. I've played around with writing enough to know that when things start to get too happy, or too perfect for a character, something drastically depressing needs to happen to that character. There is no drama in "happily ever after". It's getting to that point that keeps people reading.
This is the book that changed the series for me. Before this, I'd been mildly interested - this book had me captivated by the end.
I'd actually give this book more like a 3.5 rating - not quite a 4 star, but close. Very close.