Serial Killers are a lot like Actors

Both are professional pretenders. They can switch between emotions like cards in a deck. Their success depends on how well they execute this. Not only that, but on how well they do their research, how often they practice, and it wouldn't mean anything without that special little something that made them what they are in the first place. Once discovered, they are revered. Both are celebrities with die-hard fans and bitter enemies. Both understand the true meaning of emptiness. (You can throw that Darkness shit out the window. Everyone who knows knows that it's emptiness inside them, emptiness behind their eyes, and emptiness that begot them. All that Darkness and Dark Passenger nonsense is just for flair, or for entertainment.)

I could go on, but you get the idea. Run with it. All I'm trying to do is guide you in an interesting direction; you have to walk the path yourself.

Lastly, and most importantly, the cardinal rule is the same: If you can live without doing it, then don't do it.