I just realized that Drautus probably assigned Nyx to protect Luna so that Nyx would get attached to her somehow - so that he’ll eventually to lead the glaives to the Nif ship trap unknowingly. He knew Nyx would stop at nothing to rescue the princess, since he was the one with the “always wanting to save someone” attitude and somewhat blind to what was actually happening at first because he had a nice interaction with Luna earlier thay made some sort of bond, even if it’s short (there’s probably more interaction in the party that the movie didn’t show). And having bonded with her would just psyche him in just giving his best in rescuing her.
In other words, Drautus was technically a LuNyx shipper (LOL!!!), or at least played a subtle matchmaker for them, albeit for the wrong reasons xD. I just imagined him thinking like “Ulric and the princess… hmmm… He’ll get attached to her and she’ll be perfect and charming around him. Nice. Perfect. It’ll work” And then when the party came and he saw Nyx giving her the hair pin he’d be like “Oh yes! I knew it! Even more perfect! I can already see the heart eyes.”
It’s probably just me and my shipping goggles but yeah… it’s hard not to think about it like that LOL.