Writing Block Corner: Villains

Hello Bookworms!
So, a friend of mine actually requested that I do another writing block corner, so here I am! Today I'm covering a little something I've learned about villains. This isn't applicable to everything, but it's something to keep in mind while writing whoever ends up being the antagonist of your story.

There's a saying: a hero is only as good as his villain is evil. I think I can expound upon that. Well-written antagonists tend to be almost a flipped-coin version of the protagonist. They have gone through similar experiences to that of the protagonist, or they have similar goals, or they care about people the same way. They have to relate to each other in such a way that makes you realize that the hero could very easily become the villain. If the hero had taken a different path, or if different people had been in his life, then he would have been just like the villain. Possibly worse. That's what makes it an interesting story: seeing the dynamic of what could have been, and what prevented it. Seeing how thin of a line there actually is between hero and villain. What makes an amazingly sympathetic villain however, is seeing that in the same circumstances, we ourselves as the audience could be just like the villain. But there's a fine line between making the circumstances understandable, and excusing them. Horrible actions are still horrible, you just have to know where the blame actually lies, and make sure the characters reflect that. Finally, some of your villains might be totally not understandable at all. There are some great, crazy villains who don't have any sympathy whatsoever. (Examples: Moriarty. Need I say more?) If you know what you're going for in a villain, great. Have fun writing your first draft. If you don't though, try looking at your hero. Find what makes him or her the hero. What if they didn't have that? What if they were almost exactly the same, but they didn't have that one thing? What would be different? Would they become something terrifying? Show the audience. And show yourself.

Ok, so was this helpful? Please let me know! And if you have any requests, please let me know! I actually have a few ideas, so we'll see how this goes!
Scribe ergo quae vidiste vivere!