In all relationship questions, the outer reflects the inner. So, the starting point is, to what extent and how does my having attracted a person who appears to be narcissistic reflect me? It wouldn't be a bad idea to assume that here's a flag from the universe telling me that I need to work on my self-involvement. Narcissism is the normal unconscious condition of humans today - everybody's narcissistic. Moving past it can be seen as the name of the game. Those people who we label narcissistic are only a little more entrapped in the condition than normal. Maybe you are the same as normal, maybe you are more. But take this as a sign that now's the time to look at yourself from this perspective. As you observe your own narcissistic tendencies, you start to use the situation instead of resisting. This would be starting on the behavioral level, not yet getting down to processing. Narcissism can be considered to be a form of defending against the subconscious. Pausing that behavior, then seeing what's behind on the feeling-emotional level, then applying the Process is getting down to real work. What feelings are being stirred up by your perception of narcissism in the other? That's what you work with. When we work on ourselves, the outer changes miraculously and spontaneously. EC work does not primarily focus on how to handle the outside - it's how to handle yourself.
