Villainy most specific

Recently, I've been reading the latest novel by S.M Sterling (and by latest, I mean latest as of 2001, but I only just found it, so it's latest relative to me), The Peshawar Lancers. Despite not actually being about the Peshawar Lancers, I've been enjoying it immensely. There's lots of swords, guns, airships, villains to be killed and so on. But something has been sticking out to me.

It has to have one of the most evil villains I've ever read.

Seriously! He's a misogynistic, Satan worshiping, cannibalistic Russian who seeks to bring about the end of the world. Also, he killed the main character's father (indirectly).

This got me thinking about villains. Villains are vital for a story. Luke Skywalker is only as interesting as his conflict with Darth Vader. Without Duke Rodger's odiously evil/charismatic presence, Alanna's struggles to gain her knighthood would be lacking an essential drive and stake (beyond Alanna's personal desires, of course). You get my point.

But what makes a good villain?

Trick question!

Villains are all about specificity. You can't just grab Hitler out of a box and file off his fingerprints then stick him into a new suit. Well, you can. But that's a lot less fun! A good villain requires you to think about what kind of story you want to tell. For example, if I were telling a science fiction war story, I'd want a villain that reasonably controls an army, has politics diametrically opposed to the main character's faction, and is intelligent enough to be a credible threat. If I were telling a murder mystery, you'd want someone with a good (or at least, understandable/relate-able/scientifically explicable/coherent) reason for killing, has the ability to enact these murders, and is intelligent enough to be a credible threat. If I were telling a story set in a dystopia - and the main thrust was overcoming and destroying said dystopia - then I'd make a reason for the bad guys to be in charge, a reason for their government to be dystopic, and the intelligence to be a credible threat.

Notice a theme?

Intelligence. I've said it before to friends and publishers and random people on the street and my literature class: The most important thing about a character is that they are intelligent. And if I ever said it was something like being relate-able or likable, well, that's also the most important trait(s). But intelligence is what keeps a character engaging and interesting.

When you are reading a book and swearing at a character for doing something stupid, you are doing it wrong.

Unless, of course, I wrote the book.

In which case, you simply do not understand my genius.