I read these books one after the other so I'll discuss them broadly in a sense and on some elements of the specifics;
This series had some amount of potential. It got some good chuckles out of me and I had a nice time reading them, up until this final installment. I think I can safely say these books suffered from an issue of both scope and size; Where we should have had every element given time to breath and be explored (such as Leon and the Dragons) or Max and his Family. Where, at the end of the day, these elements felt largely superficial - Leon's dragons didn't have much motivation or anything interesting going on, they were simply just there to be used in one or two situations.
Max's family were a backdrop that done nothing really either, sure they presented "some" adversity, but weren't really anything worth thinking about because their involvement also felt superficial.
My biggest disappointment with this book was the Masque; Where in the other books he felt like a nominally neutral entity, maybe a bit antagonistic but never outwardly aggressive but then BAM! All of a sudden at the end, he's attacking the main characters because he views Leon's dragons as a credible threat.
It felt... Unneeded, it felt like it existed just to serve getting this plot point done with.
I'm not great at reviews, I apologize it's hard to articulate why this book felt sorta flat for me. The plot served no purpose, there wasn't a whole lot of interesting mystery and everything was just sorta dealt with, no real build up or threat that felt palpable. I think this book series was harmed by its poor length, maybe if it was double the pages we could've got some build-up to Dos Lunas feeling like a living place instead of just a series of back-drops the character say dialogue in.