I think this book and A Gathering of Shadows had pacing issues which interfered with the enjoyment of this inconclusive conclusion. A lot of backstory, perspective shifts necessary for sympathizing with a character, or information on the wider world (magical do-hickeys, pirate markets, international tensions, etc.), were revealed in this book, when they should have been dropped in the previous one. "Gathering" all this information /ahead/ of the climax would have made me feel like the final book was building towards a boss fight, but instead I feel as though the final book changes the margins of the world willy-nilly every chapter. A new magical item, or superpower, or martyr, is introduced so frequently, they don't feel earned; instead they feel more like deus ex machinas the author needed to pull out of nowhere because she didn't have a plan as to how to resolve the conflict otherwise.

And the central conflict remains rather vague. Is Osaron building a zombie army, and our heroes need to wake the dormant, tortured minds of thousands? Is Osaron building a copycat kingdom, and they need to understand the psychology of this villain, why he builds things, why he burns through things, what he feels he's /missing/ and has been trying to attain in the wrong ways? Is Osaron jealous of the living, and desires - King Louie style - to be like them, and therefore seeks the perfect human vessel which can contain his might? Is Osaron simply delighting in pure chaos, and rewriting the rules of reality on a whim, and our heroes have to be creative spellcasters to maneuver faster than his imagination? We don't know. The characters don't know. And the characters throw everything and the kitchen sink at Osaron, hoping to be right one time. The fetch quest, the luck of finding EVEN MORE items of power in the pirate's market, and the various sacrifices, all seemed overly convenient and woefully under-informed. Rarely, in this book, does anybody study Osaron, then come up with a plan to turn his own powers or arrogance against him, and even the ones that do, their resistance isn't effective for long. A series of cool-looking, cinematic, moments, at the end of which I reflected and thought, "Well, that was senseless, why even do that in the first place?" Very Marvel.

This is all very hard to explain without spoilers X_X;.

Aside from pacing and plot coupons, my only remaining gripe with this series is Alucard. I find him toxic and insufferable. The fact that he gets the happiest happy ending in this book, left me feeling ill. Despite his losses/suffering, he never grows as a character, never has a moment of humility, or a desire to work as a team. Meanwhile, Holland - the vessel for most of the conflicts in the entire trilogy - loses, suffers, /and grows/, earning more sympathy for the White London Antari Assassin than for King Rhy's alleged OTP. I think the whoooole series would have been fine without, or with less, Alucard; his plot arc is selfish and adds nothing to the other characters he travels with, and nothing to the defeat of Osaron.

OH, I lied, I have one more complaint: Why was Ned side-lined?! What was the point of introducing magic into Grey London, if not to call on it in our heroes' hour of need? I was expecting a magi-steampunk army to have grown up while The Reds were away defending their own London. I was expecting Red to have to evacuate, and Grey was their only hope, a ragtag band of misfits green to magic... as Lila had been when /she/ left. Lila, now Captain Bard, captain of an AIRSHIP, her fire powers used to buoy a balloon into battle! BWAHAHA! I had big dreams. High hopes... And then... Pfft. Grey London was just... /our/ London. A little Easter egg. Magic exists in tiny ways, if you know where to look for it, but no, the rest is myth... I didn't appreciate Grey being reduced to a fairytale, a wink to the reader, instead of an active participant in the plot.

All of that said, there were some GREAT moments in this book. The way the final battle mirrors the Essen Tasch. Kell x Lila on a boat <3 <3 <3. The way Kell, Holland, and Lila learn to sympathize with one another... I wish it were more than moments that I loved about this book :/.

EDIT: Reread, Review 2 -

If I hadn't lived through the pandemic, and watched people fight over how to handle a plague in real time, I might have left this book at 3 stars. But now that I've witnessed people hastily throwing out theories, untested remedies, blame - even trying to capitalize on the situation - I now understand how realistic this book was. It's not that they make a plan but then don't stick to it out of idiocy, OR that they get handed lucky doodads that the author pulled out of nowhere. It's that the world (and the history of the world) is vast, way bigger than just London, and the author (being omniscient) knew there was a vaccine out there all along, but there were too many kings calling shots without that knowledge, and they hurt each other in their blind attempts to control a chaotic situation.

I still feel like there is too much going on in this book, like there were enough PoV switches and flashbacks to easily give Alucard, or Maxim and Emira, their own books. The only backstories that felt earned and necessary were Rhy's and Holland's. I wish they had been sprinkled in a lot sooner. I kept imagining how different the trilogy would have been if, say, adapted for Netflix, and those flashbacks were included throughout.
But something I didn't appreciate the first readthrough, that I do now, is how the PoV switches mirror pure magic. Whether you picture the tapestry of threads that braid into each other, or the morphing of one element into another, people's lives aren't one, straightforward plot; they are an evolving, branching, intertwining, living story.
Similarly, I shouldn't have taken a star away for Osaron not having a straightforward manifesto. He's a creature of pure, chaotic, unbalanced magic. Of course he doesn't have a PLAN. He is always evolving his understanding of the living, and what his purpose in relation to them ought to be. Give them wonders? Subjugate them? Spread to all worlds? Stay safe in one body? He doesn't know, he doesn't need to know; NONE of us know! We rational creatures are all in flux, that is the magic in all things.

I give this book a star back, for taking aaaaaall the fairytale tropes, and instead of delivering an easy Happily Ever After, giving us a difficult and cathartic lesson about how there are no ends. We are always - often unknowingly - pushing and pulling on each other's threads, changing the tapestry, changing the flow of where the story goes.