Narcissists generally aren't interested in material power per se, they are more interested in power over their image. It's all about them. They also make horrible leaders - you do not want a narcissist as a leader, they don't care about people or the earth or anything really except their own ego.

Oh, another trait of narcissism - or rule of thumb? If you think you might be a narcissist, you probably aren't. Narcissists are completely un-selfaware. They don't see themselves as narcissists at all - and often see themselves as the victim. If you told a narcissist that they were - they'd deny it or refuse to see it. It's not something you can change or cure - there is no cure for narcissistic personality disorder.

Whedon loved narcissistic villains - Cordelia aka Beast Lady, The Mayor, and Glory all fall within that category. I'd say the Mayor and Angelus were probably the best of that group.