I liked Isobel and Nightsong. I think they're my favorite non-companion NPCs after finishing the game. I only wished they had a bit more content. That being said, reuniting them was my biggest reward in the whole game. I was smiling for the next hour when I saw them finally together after all that's happened. Saving both of them is one choice I'll never change, even if I decide to play as evil character at some point.

[Linked Image from i.imgur.com]