The Xava'tor occasionally asked for one of the Tal'darim to go with him—these volunteers were known as the "Xava'kai" ("Hands of the Benefactor") -- to help him with unspecified tasks. Tervoris became one such Xava'kai. The Xava'kai would not be seen again after leaving with Ulrezaj.
Golden, Christie. StarCraft: The Dark Templar Saga #2: Shadow Hunters. Pocket Star Books, November 27, 2007. ISBN 0-7434-7126-1.