The blue flames of House Rajha are feared by all their enemies. A special promethium is extracted from their homeworld. This promethium cannot be used in engines or for anything other than weaponizing for it corrodes the mechanisms it fuels with the exceptions of weapons. It is believed that this promethium is somehow related to phosphex, although the connection between the two is little understood. Death by the blue promethium is particularly painful even compared to normal promethium.
Two Acherons I converted from lancers for House Rajha. If GW ever comes up with a house crest for them I suppose I'll paint one on them.