Love It or Leave It?: Antagonists who become heroes / love interests?

As I begin work on the last third of Moon Dance's second draft, I have been thinking a lot about my obsession with characters who move from being an antagonist to a protagonist / hero, and of course of the reverse of this as well. I have always found the theme of redemption incredibly interesting and I know it is something that shapes my work heavily. But as much as I will admit I do write for me (at least as a first audience), I am also very curious what others think about this subject.

How do you feel about antagonists who become heroes or love interests at some point in a series? 

The most appropriate examples I can think of are Aphrodite (with Darius), Rephaim (with Stevie Rae) and Stark (with Zoey) from the House of Night series.

Avish, Kyden and Zakariah are all dealing with this in my series and making sure I set it up properly and that I don't cross a point of no return is very challenging. I always feel a deep sense of moral obligation to write something I would let a teen read if I was a parent. Yet at the same time, I am very aware that what teens are actually reading is often very different then what we might want them to be reading. It makes for some tough calls as an author, especially if part of the goal is to be true to the characters. (Which for me it is.)

Let's break this down:

Avish is the major villain in Moon Dance. Yet I've made it very clear that he ends up with feelings for one of Sara's friends, Cait. In the second book, the primary goal is actually to find a way to bring Cait back to Earth as herself so she can be with Avish. (If she reincarnates she will be someone else.) I have done everything in my power to walk a fine line with him -- he is scary when he is after Kess or Sara (which happen at different times in the book) but I have taken great care to make sure it makes sense that Cait would like him and want to be with him.

My other challenge has been with Kyden. For a good chunk of Moon Dance, his goal is to take care of and eventually pursue Sara. But he waits too long and Kess enters the picture. The things that Kyden is willing to do to regain control of his relationship (in his mind) with Sara can be pretty scary, but I make certain they do not end up together. On the other hand, has him doing things wrong with Sara precluded him being the hero for Isabelle in a future book?

Considering that I have listed evidence to the contrary, it may seem that I am worrying over nothing. Yet I know how up in arms many of us get over characters like Edward (Twilight), Patch (Hush, Hush) or Daniel (Fallen). There is a strong movement within the YA community, a collective thinking that there is something inherently wrong with these characters that could damage the people reading about them. Now, personally I am neutral with regard to this debate. I did not care for these guys, but I certainly would not go so far as to back the suggestion that a fictional character can, in and of itself, effect someone's judgement.

However, it does make for an interesting topic of discussion. Paranormal Romance tends to have many male heroes who are of a dark nature that we would generally not find acceptable if the situation was happening to us in real life. Where does the line get drawn between, "This is fiction" and "This could hurt our children?". Since different people have different reactions, it is something that seems very blurry to me. And as an author, that can make some things very difficult.

So here are my questions to you:

(1) Do you like the idea of characters going from good to bad / bad to good?

(2) If a character has been an antagonist or villain, do you feel that precludes them as being someone's love interest in a series, or do you find the shift in their behavior interesting if it is well done?

(3) With regard to the above questions, do you feel that way 'in general' or does your perspective change if you are comparing adult and YA novels? Why?

(4) On the other hand, do you feel the problem is often that a character like this is a problem because he or she is bad for the character he or she is "interested" in, rather then because of his or her past actions in a series?

(5) Can you think of any examples outside of the House of Night series?

I'd love to hear your thoughts, so feel free to leave a comment. :) I know that regardless of what I do my work isn't going to please everyone, but if the problem is the presentation of this, rather then the concept itself, that would be nice to know.