They will devalue you
Narcissists always devalue the ones who don’t give them the attention or care they think they deserve. When you reject a narcissist, they will automatically devalue you and consider you less important.
They will consider you worthless
Narcissists consider any person who doesn’t approve of them worthless. Narcissists do so when they get rejected in order to protect their egos from the serious pain that results from rejection.
They will get horrible feelings
Narcissists consider themselves superior, desirable and attractive. When you reject a narcissist, they will feel very bad and then their defense mechanisms will kick in shortly.
They might try to seek revenge
Because narcissists have very big egos, they will usually consider seeking revenge when someone disrespects them. To a narcissist, rejection is a very high form of disrespect. (See What Makes a Person a Narcissist?)
They might respond aggressively
Narcissists can respond in a harsh and aggressive way when they get rejected. Their verbal response can be harsh, brutal and very offensive.
They will hate you
Narcissists hate all of those who don’t give them attention or praise. If you reject a narcissist, they will probably hate you for it. (See Why narcissists block you?)
They might ignore you
When a narcissist gets rejected but doesn’t get in rage mode, they might silently start ignoring a person and act like they don’t exist. The narcissist might stop talking to a person all of a sudden if they feel any kind of rejection from them.
A narcissistic wound will form
If the person who rejected the narcissist was important to them then the narcissist will form another narcissistic wound. This wound will further fuel the Nnarcissistic behavior. The wound might last for years or even decades.
They will make you think you are stupid
Narcissists believe that they shouldn’t be rejected. If this happens to them, they might try to make the person who rejected them think that they are stupid for doing so.
They will try to prove you wrong
After a narcissist gets rejected, they will do their best to prove you wrong by trying to become more popular, successful or worthy. A typical narcissist might be extremely motivated to succeed just to prove people wrong.
They might threaten you
A typical narcissist might threaten the one who rejected them in order to make them change their minds. This is one popular form of manipulation that narcissists use in order to put pressure on people.
They will want to see you fail
A typical narcissist will want to you see doing really bad in life after rejecting them. According to their logic, you were stupid enough to reject a great opportunity and so you must suffer and fail.