I have a theory about the jades, the mursaat are a race of spellcasters that are supposed to be "fearful". Yet they have the jade bows and armors with them at most times. there are even jade bosses, suggesting that they have some level of authority in the mursaat army. My theory is that the jades are not"slaves" but simply mursaat that were greivously wounded in battle.(think dragoons from starcraft) They gave up there bodies but lost their ability to cast spells, which explains why they use bows and melee. I'm fairly certain that the Jades use the Mursaat skill "spectral agony" as well. If the jades are indeed slaves why would they be granted that skill?