With this review, i don't mean to criticize Sarah J. Maas as a writer or even this series as a novel. I found the writing at times very engaging and the narrative innovative. I just mean to provide my perspective, which may be relevant to readers like me. I don't see it as superior to any other opinion.
I couldn't bring myself to finish the Queen of Shadows, vol. 4. I found the storytelling all over the place. The characters were inconsistent with their personalities just shifting too much, sometimes along with their names, often to the opposite, in ways that often seemed superficial or hard to explain. The main character but also characters in general are emotional and have unreasonable responses, blown out of proportion, making them sometimes seem bratty, arrogant, and childish. It also falls easily into the commonplace of the bad guy that wants to destroy the world, impossible to empathize with. And the arc of the main character is a bit forced (she starts already as the best, there's no journey until the story forces that by giving her superpowers she still doesn't control).
My main criticism though was that there was too much use of Deus ex Machina - new characters suddenly becoming central or previously unknown facts changing the entire narrative and the way characters behave. It left me, as a reader, feeling that it hadn't been planned that way, and so to sort out the narrative, the author consistently had to bring up those unknown facts I could not have anticipated or predicted.
Overall it seemed forced and lazy in terms of storytelling and forced in terms of narrative, which is a shame because at times the narrative is interesting and powerful.
I hope fans don't take this review in a bad way. Not all readers are the same, that's all.