I believe that my sister has borderline, which is a huge part of why I haven't spoken with her but on one occasion in over 12 years. That one occasion was after our father died last year - she called to tell me (and I quote) "I have Mommy and her social security payments and you will never see her again." I said "Have a nice life" and hung up.
Do some research into Dialectic Behavior Therapy, which is about the only thing that can work with borderline.