The narc wants you to believe THE NORMAL is them and the ABNORMAL is you. Everything about them is PERFECT but everything about you is beyond IMPERFECT. As a child when we start off being the scapegoat of abuse we can either claim and accept their accusations or reject them. Unfortunately as children many are not aware of what is really going on. This can carry on through adulthood thinking "what is wrong with me". You were made to think that way because of the mental abuse.
Then we carry that ideology along with us and then it dawns on us... hey it's not me, it's them. Our defenses go up and we begin our attempt and climb against the narcissist's accusations. We tell the narc how we are not the person they are accusing us of or defend ourselves because they are coming on with full verbal attack.
We jump from "what's wrong with me" to "I'm trying to make you see what a good person I am". We still don't get the picture that they will never accept who we are because they are trying to destroy the very core of our being. The more the narc belittles and degrades, the more we go into defense mode.
They don't care a hoot about what you say, only to get you to become a little piece of nothing that exists for them. The maze of confusion and chaos is intentional, the more in control they will feel. When we have conversations or discussions usually the goal is to achieve closure. The narc never wants closure and will fight tooth and nail to maintain mind control over their prisoner.
I think depersonalization is similar to being erased, rather than the narc erasing you, it's you erasing yourself so that life can't hurt anymore, reality is too painful. It is a mixture of I don't want the world to see who I am because I am flawed (according to the narc) and if I am myself, they will doubly reject me. You live in a bubble of protection so the world can't get in, but then you feel like you can't get out, creating your own system of dichotomy.
John 14:27 27 Peace I leave with you; My peace I give to you; not as the world gives do I give to you. Do not let your heart be troubled, nor let it be fearful.