If you have met him, or if you have 5 dots in Who's Who or Occult or Theology/Religion, then your character might know this much. Otherwise, disregard all this. . .

Nubaris is a powerful guy who likes to make deals. Very few know anything at all about him, let alone his name. Little is known about his background. Some might suspect he is a vampire who tends to work outside the Camarilla laws. Others might suspect he is a mage. Among the few who know him as Nubaris, there are a few who claim he served as an archon for Justicar Demetrius. Yet others say no way.