I've watched Empress Ki several times and each time I come away with a different perspective. I initially wanted Wang Yoo and Nyang to be together -- forever. But as I re-watched I felt that Nyang's feelings for him were more about loyalty and worship of her leader. She truly cared for him, but I think because of her youth and inexperience may have confused her feelings of admiration for his leadership for romantic love. I do feel, however, think that Wang Yoo did love her in a romantic way. And is extremely protective of her.
And I could never buy into Nyang's relationship with Emperor 100% because i had trouble forgiving him for his betrayal and for hurting her so deeply. It takes a deep love to overcome that type pain, even if you can understand his reasons for doing this. And time will tell if he truly loves her for who she is as it relates to her background -- or does he just need her. It's complicated.
Tangquishi does, indeed, understand Nyang. And had circumstances been different, they might have made a great couple. I think of all the male characters he understands her best and admires her strength of character. She is not a weak woman and though it gets on his nerves, he is also drawn to her bravery and strength. it would be a nice twist of plot to see them together romantically!
I agree that Danashiri's character was well written and that the role was well acted. I also wondered if she would have behaved differently if he had looked at her. But in the end, I don't think so. She is evil to the core and her jealousy is deep seated. it takes trust to build a relationship and her insecurities would prevent that trust from happening. Plus she is El Temur's daughter and unfortunately has inherited much of his undesirable behavior.