A narcissist with power will attempt to prove in the world only what is already in his head. He can't 'see' otherwise. For him, the 'outside world' is not beyond him and does not question or challenge him and his ideas. He is the world. Others will assent to his distorted worldview, because he is powerful, not because he is believable. If he possesses any reflection, that will be exactly what will gnaw at the narcissist with power most of all: his 'truths' are inauthentic, and he is a human being without integrity. The very narcissism and power he possesses prevent him from an ongoing relationship with the truth, which begins with self-humility and the curiosity this can create in a person.