A Cluster B Personality Disorder can be one of several possibilities. The cluster is made of several disorders and until you know which one it is, the behavior and estimation of it are difficult at best
Cluster B (dramatic, emotional or erratic disorders)
I am going to make an educated elimination of Borderline and Histrionic Personality Disorders as these are more common in women. For a male, in the military, they would be most concerned about the anti-social p/d. Narcissism in the military is simply disciplined or punished into compliance so I doubt it is that.
Antisocial personality comes in various severity levels: mild, moderate and severe. Not all antisocials are violent. Quite the contrary, many prefer non-violent manipulation and deception (lying) as the main way of dealing with others. From the history you describe I would say this is the pattern you will most often see. You'll hear some truly convoluted stories, feel guilty (if the antisocial is good at it) and give more help than you should. Best protection: Make it very hard to be manipulated by establishing a no help rule. Such as: We will talk with you. (on your terms and at a location you choose and control) but we will not give you money, etc. From personal experience with clients with this diagnosis, place a fraud alert on your credit history and protect all of your identity issues such as SS#'s etc.
Bipolar Disorder is a mood based issue. Classically she will wane from depressions to elevated behavior, including (possibly) pressured speech, euphoria and unreasonable pleasure seeking. She may drug seek, be sexually preoccupied or simply spend too much money. Of the two, she has a biochemical problem that is not her fault and he has a character issue that can be helped... but rarely do those who have it, seek treatment.
If you make it difficult for them to manipulate you, they will seek easier targets.