No, it is not possible to "turn" someone into a narcissist. Narcissistic personality disorder (NPD) is a complex and deeply ingrained personality disorder that is believed to have roots in a combination of genetic, environmental, and developmental factors. It is not something that can be acquired or induced by being in a relationship with a person.
Narcissistic personality disorder is characterized by a pattern of grandiosity, a need for admiration, and a lack of empathy for others. Individuals with NPD typically display consistent and enduring narcissistic traits across various situations and relationships throughout their lives.
While being in a relationship with a narcissistic partner can be challenging and may have negative effects on your well-being, it does not mean that your partner became a narcissist because of the relationship. In most cases, the narcissistic traits were present in the individual before the relationship began.
It is essential to remember that personality disorders, including narcissistic personality disorder, are complex and deeply rooted psychological conditions that require professional assessment and diagnosis. If you are experiencing difficulties in your relationship or suspect that your partner may have narcissistic traits, seeking guidance from a mental health professional can be helpful in understanding the dynamics and exploring healthy coping strategies.