There is not much known aboout Thuringwethil, but we do know that she wielded power - and that is practically an invitation for any fanfic writer. And she is so much more than 'just' a vampire (even though I did put in just the tiniest hint!). And as much as I love vampires (and I do), it is not her defining trait. Personally, I see her as a lesser Maia, choosing Melkor's side just like so many others did, and this is just as much a character study as a real story.

Thank you! Thuringwethil was canonically a messenger, but that got me thinking, what was she doing in Minas Tirith, an occupied enemy fortress, in the first place? And so this idea was born. And Sauron is the one running Angband on a daily basis; it would be impossible to rule a fortress of that size without laying down some hard rules. Those rules don't apply to himself, ofcourse, but that's to be expected ;).

Perhaps, but it is not Thuringwethil who suffers for it :)

Thank you! I do believe the text says a great number of Maiar chose Melkor's side; once again, history is written by the victors (and survivors!).