Personally - I'd like to read your take on Thurngwethil.
She is such a briefly mentioned character by Tolkien; I'd like to see what you might do with the 'Woman of the Secret Shadow'.
I'd also say, let's assume she was a Maia and it would be interesting to see Morgoth taking her back under his wing and grooming her to play her part in the downfall of those dratted Elves.
I can almost hear the sadistic yet seductive
MWAHAHA . . . echoing from the darkened sky as she flies off on her appointed mission.
~*~ pio