Have to agree with Choklad on Amukiki. He's actually my favorite romance for Saren, oddly enough, but I feel like his route is one that has to be played all the way through for it to be really appreciated (unless you've already done that and still don't like it, in which case you can disregard this entire paragraph
) . There's a lot he isn't willing to admit about his personal feelings and desires, both to himself and to Saren/Elenor. And it's because of that that for most of the romance he comes off as rude or uncaring.
I personally felt like the real breakthrough with him only happens during the big confrontation (/slash/ angry sex scene) toward the end, at which point the tone of the relationship completely changes, which becomes especially apparent in the epilogue. But if you didn't get to that point, I can absolutely see how you would think of him as trying to undermine Saren/Elenor, even if I don't feel that's the case ultimately. So yeah, I'd recommend giving him another go.
And I suspect we might just have different tastes in love interests (nothing wrong with that!), because despite him being one of the most interesting routes to play for me, Mesphit actually struck me as one of the least
healthy relationships in the game, at least for Elenor. It's pretty much the only reason I can't in good faith call him my favorite, though he gets pretty darn close. My memory of Saren's interactions with him are a little fuzzy, but I do remember thinking something very similar for Elenor/Mesphit that you do with Saren/Loren, that Elenor has this overwhelming feeling that Mesphit is a good person deep down, despite him not having done much at that point to indicate it.
Even though she turned out to be right in the end, her constant insistence of it, even when he continuously pushed her away, and even got violent with her at one point, struck me as a bit...I dunno. Self-destructive, maybe? Not sure what the right word is for it. So while I can definitely see how Mesphit is able to heal and grow through his relationship with Elenor, I'm not entirely sure that it equally benefits her.
Don't get me wrong, I love the romance as a whole, but by the end of it I still had this lingering feeling of "eehhh wow, this really isn't a very healthy relationship, is it?" But again, I think I just read the situation in a different way. I have faith that Mesphit will only continue to conquer his demons, both literally and figuratively, in the second game.
As for Rei, I will say that it is possible to change his view of dark elves, and even get him to realize that Mesphit is not his enemy. I don't think you even need to be in a relationship with him to do it. His romance epilogue is super cute though