When you write romantic suspense, you want the reader to fall in love with the hero. He has to be sexy and appealing. Not necessarily wildly handsome. But he’s got to have something that will connect strongly with the reader.
The other major male character in the story is often the villain. And you’ve got more leeway with him. He can be handsome or downright ugly. He can be charming or grating. He can be outwardly friendly to the h/h or outwardly hostile.
But you’re walking a fine line with this guy. (Usually he IS male, although you can have some very compelling female villains.) If you make him pure evil, then he’s going to be less interesting to the reader. Still, you want the reader to be rooting for his downfall.
I try to give my villains a background that helps the reader understand how they got so bad. I think one of the best examples of this is the killer in Thomas Harris’s RED DRAGON. He had a harelip and a speech impediment, so the kids made fun of him when he was little. And he was raised by (I think) a grandmother who was absolutely horrible to him. In the middle of the book, when he has a love affair with an innocent woman, you’re half hoping that he can go away and have a happy life with her, even when you know that’s going to be impossible.
Right now, I’m writing a Berkley book with a powerful bad guy who had a miserable childhood which makes you understand exactly why he turned out the way he did. The hard part here is that–um–how can I say this without giving away the secret of this book? He’s going to be the hero of another book. So I’m walking a fine line with him. He has to be bad enough to make a formidable enemy now. Then the reader has to understand how he gets rehabilitated. It’s an interesting challenge.
Which brings me to the question–what do you want to see in a villain? And how do you feel about a villain ending up being the hero of another book?