The necrons of tomb world valess are jealous of other beings who have souls and like the vampires the resemble seek to turn all organic life into their kind ridding them of their souls and flash they are attking your planet a forgotten chapter of the empire of man that is one of the more advanced fetulie world in that only their culture is midevile they have tech priest, a space marine chapter and a lot of dark age tech but that last ones of fir warriors and nobles you get the choose your social class and how bone you are or how much ass you can kick