“The narcissist views his partner as an extension of himself, except his partner is an inanimate object, not a living creature in his eyes. The narcissist needs his partner to provide a regular flow of supply to feel worthy, superior and good about himself. The slightest disagreement, criticism or difference of opinion is perceived as an assault on the existence of a narcissist. Differences of opinion are viewed as an outright attack on the false persona he has carefully created.
Any suggestion, belief or opinion that contradicts his false-self is not tolerable and the narcissist will do anything to defend his points of view and demonize yours. His manufactured false image is dependent upon his partner to sustain. He’s driven to devalue his partner because he despises his dependence on her as much as he is dependent on her. Devaluing his partner is the only way to disavow the unwanted dependent feelings while maintaining his sense of superiority and control.”
Source – https://relationshipedia.me/2015/06/10/happily-never-after-decoding-narcissistic-devaluation-and-deceptive-abuse/