Ah, got it, full moon Libra-- but then wouldn't this include millions of people? If I think of the typical high school class cohort, everyone born with the opposition (and can we allow a 10-degree orb, or a full 20 degrees around the exact opposition?) would know a fair number of people with this synastry relationship. Of course, some people are paranoid, easily victimized, "black sheep", and so on; but I was born with a sun-Pluto opposition, so virtually everyone in my high school or college class would have Pluto opposite my sun.
Vista, I've been thinking a bit about Pluto, with the Uranus square Pluto transit currently in force. I really think Pluto has a lot to do with domination, in a "dominate or be dominated" way. Pluto isn't about making nice, getting along, compromising, or give-and-take. So I am not surprised by your friend's experience!
I did once know two Plutonians who were a stable married couple. Somehow they seemed to understand and admire one-another's profound intensity. I suspect they were able to channel their Plutonian energy outside the relationship. Interestingly, both were university administrators, so they got to register their personal power on the people they supervised. But in a constructive, collegial sort of way.