For precise answer? Err, I'd say the lesbian vampire romance/bad ending part :P I saw your encounter design and artwork, then told myself: that is rather inspiring, more projects should do that.
So, there is 1 particular quest in the mod, a murder investigation which may lead player directly to the "evil" vampiress. If player is a female with right stats, she can be converted (instead of the standard bribe/fight option) to solve the conflict. That's it, nothing else.
As I said, it's a huge Morrowind (The Elder Scrolls 3) free mod with 80 quests, and I try to implement many cool vampire ideas. If you think it's appropriate for me to post a link, I could do that. Alternatively (and I'd rather do that), I could PM it to you, because I don't wish to use your comment section for advertising.