This book was alright. I expected a lot more from it after the first book. I mostly felt like Dead Things was a pretty good book with some big and some small flaws that might improve as the series goes on and the writer gets more comfortable with the characters and world. I think some of the minor things are cleaned up to an extent, but some of the major issues are still there and even some of the things I liked in the first book are lacking in this one. Ultimately, we're left with a book that is definitely an improvement in some ways, but still ends up being a step back because of other issues.
On the minor end, I think Eric and the minor characters are more interesting than in Dead Things. Eric is still mostly an asshole, but he's a BIT more likable in this book. That said, he does go on a GTA style temper tantrum and shoot a stranger's car because he didn't like them honking at him for standing in the middle of the road. But at least he admitted that he probably shouldn't have done that. Baby steps. There's also a noticeable decrease in the overuse of the f-bomb in this book, which makes his voice a touch less eye-rolly.
I enjoyed the minor characters in this book a lot more than in the first book. I think they could still use some work, but Dead Things was severely lacking in this department in my opinion and this book has at least decent minor characters. I also liked that we got an attractive female ally who wasn't just a love interest and had her own motives and alignments, though I ultimately didn't like her as much as I thought I would. The villains are better than in the first book. They aren't great, but I thought the villains in the first book were its biggest flaw as they were pretty lame and idiotic most of the time, so I'm glad Broken Souls wasn't a repeat of that at least.
Unfortunately, Eric's still not very likable. I think that's okay to an extent as he fits the story as (sort of) an antihero that fits the darker setting and plot. And despite being a dick, he's not completely a raving sociopath (other than stealing random people's cars repeatedly with no real moral qualm). But without more, he's left not being as interesting as I would like. I find myself mainly only rooting for him because I want to see things develop, not because I particularly want to see him succeed.
Another major qualm for me is that I was hoping the magic would be explored in a bit more depth with more clarity than in the first book, but it wasn't really.
I expected the Santa Muerte storyline to develop a lot following the last book. I was a bit disappointed that Eric's first choice was to try and be rid of the bond before he really has much idea what all it entails. I don't think it's an irrational decision as they didn't exactly get together on the best terms. But still, the book is clear that Eric's bond gives him significantly more power. Being the egotist he is, I would've liked to see him indulge in and enjoy that power a bit instead of immediately trying to get out of the whole arrangement. As I said, the terms and conditions of the arrangement's coming to be were pretty shitty though, so I can't say it was an unreasonable decision.
I won't say too much on how the Santa Muerte storyline develops since that deals with some of the bigger spoilers of this book, but I do think some of it's fairly interesting and alarming. Plus, it develops more of the whole Aztec mythos that I think makes Eric Carter as a series stand out a little better instead of just dealing with cut and paste werewolves and vampires.
The main plot of this book felt a bit flimsy to me, which was my biggest disappointment coming off the first book, which I think, despite its flaws, had a strong and fast-moving plot throughout. Even now, I'm having a hard time even remembering it since there wasn't much to it. Eric's up against some kind of shapeshifter with a magic knife and he and his sidekick are bad. He has to team up with some new allies (who seemed to just pop up in the world since he's burned so many bridges in the last book) to do this. So they face off. I feel like a lot of the plot was very reactionary on Eric's part. That doesn't always bother me, but it felt excessive enough to be annoying to me here. I also just feel like the plot didn't really develop at a steady pace, perhaps because there was much less of a mystery element to the plot than in the first book.
Overall, this isn't a bad book, but I did feel that while there were some improvements, it was a step back from the first book. I'm still willing to read the next book and I wouldn't say I regretted reading this one, but I do wish it had been better.