You're awfully clear that you're the good guy in this narrative. Of course, we don't get your ex-wife's side of the story. However, as a child of divorce myself, Imma go with you did some things that made the kids feel bad. I don't think brainwashing is a good explanation. The thing I've learned about kids (after having been one and raising a couple) is that they're full human beings from the get-go. They know what's up at surprisingly young ages. Try a little circumspection, starting with the assumption that you were in fact the narcissist in this story. Play that out and see if it fits.