I think a narcissist rages when it becomes clear to her that you are escaping her trap, that all the hard work she has done to pull the wool over her eyes has failed. This is a major setback, since you are the target for whatever she has in mind--money, favor, housing, etc. She is enraged that you have seen through her cleverly-constructed hoax, and it a blow to her self-esteem. She becomes so angry, she wants to hurt you, kill you, or, somehow, get rid of you. Been there, seen that.