Mirroring is a major Psychological Manipulation Technique used by Narcissists, to quickly establish Rapport and gain your Trust.
Narcissists are not One Trick Ponies. They have many tricks up their sleeve.
In this video Derren Brown shows the use of Conversational Hypnosis to pay for goods with “blank pieces of paper”. Your Narcissist could use the same techniques to reframe your mind so you will continue to “Trust” them, no matter how much they have betrayed or hurt you.