"Who's fairest of them all?" – asks Bad Queen in fairy tale. Having provided wrong answer, mirror is smashed to smithereens. Not a bad allegory for how narcissist treats his "friends".
Literature helps us grasp intricate interactions between narcissist and members of his social circle.
Both Sherlock Holmes and Hercules Poirot, world's most renowned fiction detectives, are quintessential narcissists. Both are also schizoids – they have few friends and are largely confined to their homes, engaged in solitary activities. Both have fatuous, sluggish, and anodyne sidekicks who slavishly cater to their whims and needs and provide them with an adulating gallery – Holmes' Dr. Watson and Poirot's poor Hastings.
Both Holmes and Poirot assiduously avoid "competition" – equally sharp minds who seek their company for a fertilising intellectual exchange among equals. They feel threatened by potential need to admit to ignorance and confess to error. Both gumshoes are self-sufficient and consider themselves peerless.
The Watsons and Hastings of this world provide narcissist with an obsequious, unthreatening, audience and with kind of unconditional and unthinking obedience that confirms to him his omnipotence. They are sufficiently vacuous to make narcissist look sharp and omniscient – but not so asinine as to be instantly discernible as such. They are perfect backdrop, never likely to attain centre stage and overshadow their master.
Moreover, both Holmes and Poirot sadistically – and often publicly – taunt and humiliate their Sancho Panzas, explicitly chastising them for being dim-witted. Narcissism and sadism are psychodynamic cousins and both Watson and Hastings are perfect victims of abuse: docile, understanding, malignantly optimistic, self-deluding, and idolising.
Narcissists can't empathise or love and, therefore, have no friends. The narcissist is one track minded. He is interested in securing Narcissistic Supply from Narcissistic Supply Sources. He is not interested in people as such. He is incapable of empathising, is a solipsist, and recognises only himself as human. To narcissist, all others are three dimensional cartoons, tools and instruments in tedious and Sisyphean task of generating and consuming Narcissistic Supply.
The narcissist over-values people (when they are judged to be potential sources of such supply), uses them, devalues them (when no longer able to supply him) and discards them nonchalantly. This behaviour pattern tends to alienate and to distance people.