The advantage to knowing that someone is a narcissist is that you can quite often anticipate their behaviour. People with Narcissistic Personality Disorder can be very predictable in their actions and reactions, so you could, if you wanted to, use this knowledge to your advantage.
Of course, each narcissist is an individual with their own unique traits. Maybe the one you know is invested in being seen as superior; maybe they always need to be right; maybe they need to be seen as a “good guy.”
Knowing what the narcissist in your life values and desires can enable you to be strategic in your dealings with them. You can use this knowledge to make certain choices that would evoke more optimal outcomes for you.
You must remember that the narcissist is never driven by love, compassion or empathy. They’re always self-focused and self-serving. If you let go of your hope that they behave like “normal” people and see that they march to the beat of a very different drummer, you can get the upper hand around the narcissist(s) in your life.
So the answer to this question is yes, a narcissist can be fairly easy to manipulate. If you understand what they want, how they typically respond and what they want to avoid, you could theoretically bring out behaviours in them that would suit your particular needs.
The bold was my editing and sorry if I quoted more than the standard number of words but I thought it was important to see the whole.
_________________________ ignorance is the enemy without equality there is no liberty