To maximize your reader's emotional experience of your story, you must put a face on your protagonist's enemy. When this is done well, your reader feels something for the opposition as well as for your protagonist. You want your reader to feel intense, conflicting, and complicated emotions about those forces of opposition. You can evoke those feelings in five ways.
1. Know your opponent's history. Know what motivates them to act and speak the way they do, and let the reader know, too.
2. Give your opponent a positive personality point.
3. Make your opponent believe he is right (even if he isn't).
4. Show the world as the opponent sees it.
5. Show his face. Many authors forget to provide their antagonists with character markets and physical descriptions.
The more often your reader sees the opponent, and the bigger his or her role, the more clearly you should show who that opponent is.