Responses
They've already established nikolai as a deuteragonist for both adrian and anastasia, mostly adrian, as a representative of optimism where both of them lacked, especially adrian severely. I think it was inevitable for them to end up as a 3P with a plot like this, though the center of it will be adrian for the most part.
There was NO point to make them a three person couple at the end. Literally NO POINT. Anastasia and the prince were clearly very in love, why tf the knight had to be involved made 0 sense. This book down hill fast, which breaks my heart