All of the Romance endings in Throne of Bhaal were obviously written with a good-aligned character in mind. Romance Anomen and you get 'treated' to an epilogue where a bunch of celestial envoys attending the marriage of the new goddess of Murder...
Viconia being the only evil romance option and
having a redemption arc was sadly pretty predictable. It's a pretty tired and well-worn troupe at this point to redeem evil party members and especially romance options. The reverse is much rarer. I never followed the Nathyrra*
romance in HotU, but I do
remember that if you went with the evil option for the middle third of the game and sided with the Valsharess you lost both her and Valen side against you no matter what-costing you half of the endgame companions and romance options right then and there. Think that say a bit about common design principles of rpgs when it comes to romance right there. of note, the only romances you lose out on in BGIII by siding with the druids is Minthara herself, whereas you lose three (Wyll, Shadowheart, Gale) if you side with her.
I regards to Minthara and her romance, I think the voice actor did amazing voice work for her-her voice is really saturated with emotion when she confesses her love.**
At the same time I *do* think that her whole 'relationship' (for lack of a better word) feels really.....accelerated. compared to all the other characters you can romance, you barely interact with her-talk to her three times and suddenly wants wants to be with you forever! We are like halfway through the first act and we are getting this emotional confession of love (she basically proposes to you, really) that feels like it should be the sort of thing coming in sometime in the final act after journeying with her for 20 hours. Like I'm not sure where they can go with that relationship from there? I'm kinda concerned that her arc feels so...rushed so far because they don't have particularly long-term plans for her...
Honestly, I think she's likely to get killed off in the Act I finale or something like that. Probably her tadpole triggers and she spontaneously turns into a flayer or some sort of emotional suckerpunch like that. IIRC even when you convince her to not turn on you, she never seems to gets clued in that you aren't a follower of the absolute, and there's still the matter of the one in her head as well. That's a lot of convincing we need to do when we aren't even going to be seeing her again by her words until after moonrise towers, when presumably the poo hits the fan and we need to get the tadpoles out NOW.*
Bit odd trend that Minthara is the third Drow female romance option so far, but I can't think of a single male drow party member, much less romance option in any games. Also, I don't think there's ever been a recruitable follower of Lolth in any game either. Gotta be a Drow Lady, but not too
evil, so they have to have turned away from the Spider Queen and need to have a soft and sentimental side. *shrug***
It does feel really weird that she shows her sentimental and soft side right after having you butcher a bunch of defenseless innocents. A bit tonally off IMO.