Villains can do all sorts of nasty things to player-characters. That’s why we love them and hate them all at the same time. Villains also seem to have more fun than heroes, which is why we writers love to write them!
Antagonist: The opponent or adversary of the protagonist.
I try not to state out-and-out rules in this book, but here’s one where I can’t help myself: the antagonist must be every bit as intelligent and powerful as the protagonist. A weak adversary creates a weak hero. Never ever ever make the mistake of giving the villain an obvious weakness in the same way we lame a tragic hero with an Achilles heel.
This rule is so important that Egri repeats it twice on the same page:
The antagonist in any play is ...