I've often felt that super villains' obsession with heroes must be because they secretly want to/have bone(d) them. After all, they're the first ones to tie them up and do kinky, sadistic things to them. And even though the heroes' lives are supposed to be in danger while in captivity, have you ever heard of a hero that didn't survive, or didn't recover from the experience? They've worked out a safe word to prevent that from happening, I tell you. Most villains are sadists (e.g. they enjoy inflicting harm on others) and most heroes are masochists (e.g. they're the first to throw themselves in front of a bullet). They're perfect for each other!
Yeah I know. Why are the original character and the evil twin bent on each others destruction? The know each other so much more intimately than anyone else ever will.