Female villains in romance novels come in a class of their own. For example, it’s fairly simple to pluck a male baddie out of the bargain bin at the Obsessively Misogynist Murderous Rapist Barn to provide some last-minute conflict, but female villains with actual rap sheets are relatively rare.
But that doesn’t mean that they can’t be effective and dangerous adversaries; female villains tend to be more intellectual, and their weapons rely on carefully-chosen words or manipulations. The wounds they inflict, therefore, are often internal. Instead of attacking a protagonist outright, they’ll simply wear away at their self-esteem, their confidence, their trust in themselves and the world around them.
That being said, after spending years reading romance (for science!), I’ve noticed that the majority of female villains tend to fall into one of these five types: