My understanding is that most people with (traits of) one PD also have (traits of) another PD. A lot of what I see being attributed to pwBPD or pwNPD seems more like Antisocial Personality Disorder to me.
Since questions of antisocial motive come up so often in our postmortems (i.e. ex acted with intent to hurt), it seems like it would be useful to review the criteria for APD.
https://bpdfamily.com/content/antisocial-personality-disorderAntisocial Personality Disorder Diagnostic Criteria 301.7 (F60.2)
A. A pervasive pattern of disregard for and violation of the rights of others, occurring since age 15 years, as indicated by three (or more) of the following:
1. Failure to conform to social norms with respect to lawful behaviors, as indicated by repeatedly performing acts that are grounds for arrest.
2. Deceitfulness, as indicated by repeated lying, use of aliases, or conning others for personal profit or pleasure.
3. Impulsivity or failure to plan ahead.
4. Irritability and aggressiveness, as indicated by repeated physical fights or assaults.
5. Reckless disregard for safety of self or others.
6. Consistent irresponsibility, as indicated by repeated failure to sustain consistent work behavior or honor financial obligations.
7. Lack of remorse, as indicated by being indifferent to or rationalizing having hurt, mistreated, or stolen from another.
B. The individual is at least age 18 years.
C. There is evidence of conduct disorder with onset before age 15 years.
D. The occurrence of antisocial behavior is not exclusively during the course of schizophrenia or bipolar disorder.