Some while back I wrote a post on the outworking of the villainous mind and on three critical points of his character – his motives and goals, his means of achieving those goals, and his opportunities to put those methods into action. If the antagonist is lacking in any one of these, he has failed at his purpose in literary life, which is to make the protagonist’s life as miserable and his subsequent triumph as glorious as possible. Much as the villain would like it to be otherwise, that is his true raison d’etre. Motive, means, and opportunity are the pillars of his life.
These points, however, are fairly intuitive and require little discussion: we all know what the villain is there for, and we all know that in one way or another he and the hero must butt heads. It is, to quote Darth Vader, his destiny. On a certain level, however, this is mere coincidence. The hero and the villain are tossed together; the hero crosses the villain; the villain retaliates; and so the world spins down. There is no real connection between the two. It is the old story of the knight with the monster, or the more recent story of the hero with the evil overlord.
Such a dynamic has been and can be done quite well, but the interesting thing about the villain-hero relationship is that, when you begin digging, you find it goes much deeper. You find it isn't coincidence after all, and it isn't that the two just happened to peeve each other. In some of the best villains, there is a marked parallel to the hero. The phrase is cliche now and I don't recommend employing it, but it is no accident that "We are not so different" is a common remark from the antagonist to the hero.
To snatch an example, when we think of The Lord of the Rings, the main villain that springs to mind is Sauron himself - but for most of Frodo's journey, his closest antagonist is actually Gollum. Sauron is way off in Mordor; Gollum is right there by Frodo's side. And Gollum, unlike Sauron, has a close connection with Frodo. Both are hobbits, both ring-bearers, and Frodo feels the same pull toward the Ring that destroyed Gollum years before. In situation, they really are "not so different," and that is what makes Frodo's eventual triumph so much more poignant. Gollum serves as the backdrop for the heroism of Frodo.
There is a quote attributed to Tom Hiddleston, the actor who played Loki in "Thor" and "The Avengers," that has been making its rounds of the internet recently: "Every villain is a hero in his own mind." But there is a flipside of that, for I think that every hero has a bit of the villain in his heart. We don't like to realize it; it makes our heroes less pristine, makes them more brutally honest and more like the villain than we are comfortable admitting. We want the two to be separate, but oftentimes there is little that makes them to differ except the state of the heart - and when you get down to that bedrock, it makes both characters stand out in starker relief.
but there is a spirit in man,
and the breath of the Almighty gives him understanding.