In short, a narcissist does not see other people as human beings. They don’t consider others as having their own distinct set of needs, wants, and emotions which deserve acknowledgement or respect. To a narcissist, other people are mere objects, and their only purpose is to serve the narcissist with a steady stream of adoration known as narcissistic supply.
Because of their inability to recognize the humanity in those around them, it is not hard to understand why some of the biggest perpetrators of evil in the world have been malignant narcissists. Dehumanization of others is almost a prerequisite for large scale evil such as genocide and torture.