Originally Posted by GTA:SWcity
Well, isn't there that one mention by canderous in K1 that it hadn't originally been the mandalorians' idea to attck? Shem brought up some pictures of it some time back... Something about a mention of ancient sith that sealed themselves away from the galaxy after the war started. Still could have been idealist remnants, as that vader-malak-esque guy in the Deceived trailer looked to be still pretty human.
True, but I think there's a good chance that Bioware may have had the remnants of Exar Kun's Sith in mind at the time. We know from various sources that some of these Sith survived into the time of the Jedi Civil War and were integrated into Revan's Sith Empire (Darth Sion being one of them). Their numbers may have been stretched thin at that time, but it's very possible that there were enough of them left over during the Mandalorian Wars to have still posed as significant threat.
At least at the time the game was produced, that is. They may very well be retconning that line to refer to this enigmatic faction that sprung from those who fled the Great Hyperspace War, whom Kriea dubs the "true Sith." There's a strong possibility that this will prove to be true, but I've always highly doubted that Bioware had these "true Sith" in mind when writing the first game.