I'm actually really pleased with this page. How it is able to tell a story without a hell of a log of dialogue.

You'll note (if you haven't already) that the D.O. don't call themselves "dhampir" nor refer to each other in that fasion.

As with the United Territories there is prejudice against dhampirs in Europe, and the title is often derogatory. So Dominic's use of the term means he's really pissed and excluding Cabal from their "Fraternity".