Narcissists have no enemies. They have only sources of narcissistic supply. An enemy means attention means supply. One holds sway over one's enemy. He seeks you out probably because he has absolutely no other NS sources at this stage.
Narcissists frantically try to recycle their old and wasted sources in such a situation.
First, you get over the excitement of seeing him again. It is flattering, perhaps sexually arousing. Try to overcome these feelings. Then, simply ignore him. Don't bother to respond in any way to his offer to get together.