I understand this so much or how they feel like villainizing the person that hurt you is supposed to somehow make you feel better.

YES. I think of it as a “convincing-yourself-that-you’re-really-done-aka-moving-on-faster-though-it’s-not-too-logical” thing. But if it extends to the point where it’s an almost daily (or just daily) thing where you can’t seem to stop feeling any kind of blind rage, then there’s a problem.