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 out his old sources of narcissistic supply when he has absolutely no other NS sources at his disposal.
Narcissists frantically try to recycle their old and wasted sources in such a situation.
If you are an old source of narcissistic supply, first, get over the excitement of seeing him again. It may be 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.