But is taboo-breaking violence the only (or even best) way to define a villain? I think not, in many if not most cases.
Do villains have to commit “taboo” acts for us to hate them?
Do villains need to rape, torture or mutilate people for us to hate them? Or maybe the reverse is true: Sometimes we can invest more in a villain, if his or her evildoing is creative and leaves more to our imaginations. Sometimes with villains, brutality is the lesser path. Here’s our plea for more subtle monsters.
Aladdin: Return of Jafar.
Aladdin is facing off against Jafar in genie form. Aladdin's like "You can't kill me!" and Jafar says, in what is the darkest line I've ever heard from a Disney flick, "You'd be surprised what you can live through."
Violating a taboo is a cheap way to make a villain. A better way is for you to like the character, and have them betray you. There's really not much more arousing than when a trusted friend becomes a bitter enemy.
The veiled threat that stirs the imagination is better than the laundry list of horrors. Yup.
Violating a taboo can work, and sometimes it may very well be the "right" way. But it's also a very blunt instrument, and it makes it the more difficult to up the emotional stakes or reinforce the villainy at a later state.