Malignant narcissists can be highly manipulative, and they don't care who they hurt as long as they get their own way. They generally don’t care about the pain they cause others—or may even enjoy it and experience it as empowering—and will do what it takes to prevent themselves from loss, inconvenience, or failing to get what they want in any situation.
They see the world in black-and-white terms, including seeing others as either friend or foe. They seek to win at all costs and generally leave a great amount of pain, frustration, and even heartache in their wake. Among the variants of narcissism, however, malignant narcissists are by far the most damaging.
While there is only one official diagnosis for narcissists, there are different "variants" of narcissism or different types of narcissists, and narcissism comes in varying degrees of severity. A 2012 review of the research on narcissism identified several of these variants including grandiose narcissists, who seem to require excessive praise and attention, and vulnerable narcissists, who tend to have a lot of anxiety and need a lot of supportive attention.
In fact, some experts see little difference between malignant narcissists and psychopaths in that both have a sadistic, antisocial streak, and very little empathy. There is often some paranoia involved with malignant narcissism as well. Signs and symptoms of narcissistic personality disorder (NPD) and the severity of symptoms vary. People with the disorder, particularly malignant narcissists, generally:
Care quite a bit about their appearance and can come across as quite charming
Expect to be recognized as superior even without achievements that warrant it, and will discount any evidence that doesn't support their belief of their own superiority
Exaggerate their own achievements and talents, even to the point of lying
Are often preoccupied with fantasies about success, power, brilliance, beauty or the perfect mate
Are highly manipulative
Tend to project their bad behaviour onto others, meaning they may accuse you of the very behaviour they are conducting
Monopolize conversations and belittle or look down on people they perceive as inferior
Aren't opposed to taking advantage of others to get what they want
Fail to see or value the needs and feelings of others
Have no remorse for hurting others and rarely apologize unless it will benefit them in some way
Insist on having the best of everything and believe that they deserve this
Can’t handle criticism and lash out if they feel slighted in any way
Have a poor sense of self and weak ability to regulate their feelings and actions
Secretly feel insecure and have a week sense of self
If the description of a narcissist sounds familiar and has you concerned, this is probably a good thing. Knowing that you may be dealing with someone who could hurt you and having some concern for yourself in this situation can help you to protect yourself from the pain that a malignant narcissist can cause, at least to an extent.
Extract from https://www.verywellmind.com/how-to-recognize-a-narcissist-4164528