Yep never liked her since beginning. Also Yoonsoo doesn't trust her either infact my guy doesn't trust anyone but.. he will still follow everything ChaeAh says❣️haha.
So I'm guessing he has a plan or something cz we can see Geurim is in a unstable stage and Rose has already captured a tiny part of his heart/mind at the beginning with her real/fake kindness. Hence he is letting him go and gain experience cz that's how he learnt everything to hunt. He's not a mixed blood his kind is just a servant to the father they are not treated well like Rose or Leo. Yoonsoo gets attention just bcz he became powerful. So that should be i guess 😅