Joséphine
The trouble I had with the language was that it gave me the distinct impression of trying too hard. The use of some archaic terms like "yestereve" and "the morrow" to evoke an old world setting fell flat with the use of otherwise fairly modern expressions and expletives. The prose itself was painfully longwinded, at times without actually conveying any form of information. That's even without considering the multitude of footnotes. I did listen to an interview though, where the author mentioned that he included footnotes for readers who wanted to immerse themselves even more into the Nevernight world. It was entirely entirely alright to skip them.
As for the story? As much as I liked the idea of an assassin school, the execution made it nigh impossible for me to be invested in Mia's life and the people that she met. Had I stuck to the hardcover, I would've had to give Nevernight 1 star or no rating at all (due to DNF) but the narrator does deserve some recognition, hence the additional half star.