Going to make this a review of the series as a whole. It was surprisingly better than I expected - I've gotten VERY disillusioned with "The Special Child and His/Her Special Horse/Pegasi/Unicorn" subgenre - and I finished the series quickly. I enjoyed the characters and their development; the Sandwen culture was intriguing; and the conflict and setpieces were engaging. However, imo, the first series was better, especially comparing the final books of both.
One of my biggest issues was how BtWC wrapped up too quickly. **Minor/ Major Spoilers** What becomes of I'Lenna and her family? Why didn't we get to see the future of Fifth Clan and Storm Herd? Also, the way Rakkhi lives among the giants is rushed, too. Not only are the cultures not fleshed out as much as they should've been, but one (admittedly big) mistake from Rakkhi and, boom, they're just simple antagonists until the end of the story. It's just so reductionist, and it reads like the authoress just really wanted to be done by the third book.
Honestly, this last book would've really benefitted from two or three more chapters, and I think that making it another quartet (like devoting a book to Rakkhi and the giants, or split it between that, Rakkhi surviving the jungle, or hiding out somewhere in Daakur) would've done wonders. And on that note, some pieces of the plot just fall a little too easily into place. Some of the luck Rakkhi encounters, especially since these books never get too deeply into magic or the religion and spirituality of the Sandwen peoples, is just unbelievable enough to break my immersion. It isn't terrible, imo; just noticeably contrived. If he'd matured more and gained more skills either with the giants, journeying through the jungle, living among another culture, or all three, and some of those bits of luck were him applying more of what he'd learned instead of pure fortune or vague foreshadowing, it would've left a sweeter taste in my mouth.
Overall, though, this is a good addition to the Guardian Herd series, if missing some of the potential I'd come to expect since the first series. I look forward to more, especially a series about Riversun.