Is a particularly promising blend of cognitive behavior and psychoanalytic techniques, which has been used to treat clients with borderline personality disorder?

I believe the answer is: Dialectical Behavior Therapy (DBT)

Dialectical Behavior Therapy (DBT) was first developed by a psychologist name Marsha Linehan. This therapy is aimed to make the participants develop necessar cognitive and psychosocial skills that allow them to adapt to group settings and work together as a team.