Normally, when someone we love is turning away from a struggle, we self-protect by also turning away. That's definitely my first response. I think change is more likely to happen if both partners have common language and a shared lens to see problems.
When I look at narcissism through the vulnerability lens, I see the shame-based fear of being ordinary. I see the fear of never feeling extraordinary enough to be noticed, to be lovable, to belong, or to cultivate a sense of purpose.