The Dark Side priests were once the rulers of an unknown jungle planet which the Dark Side pyramids were located on. The people of the planet found control of the Force easy, and many of them studied the light side. Others, however, chose the dark side and soon overpowered the followers of the light, forcing them into hiding and hunting them. Over time, the dark priests became the overseers of both the government and religion on the planet; the strongest six became the Dark Side priests and were like unto gods. And, as gods, they thirsted for war and death for those who would not bow to them and cower under their heel. To this end they established a system of daily sacrifices and, if there were no chained enemies to slay, then they would simply choose one of their own followers by a lottery system. Sometimes hundreds were killed in a single day.
As the priests killed using deadly Force techniques, the stench of the dark side settled into the Altar of the Dark Side on top of the largest pyramid where the sacrifices were made. Over time, the foulness of the stone became so great that the souls of the dead were stuck inside it instead of being able to become one with the Force. Over the course of 2,000 years, the death and war continued unchanged. Through all this time there were always a few servants of the light who tried to fight against the dark priests. Unfortunately, in time, any who served the light were found and sacrificed. Master Zik'tath was one of the final 100 who were sacrificed.
Shortly after Zik'tath's death, however, civil strife and rebellion struck the planet and the dark side manifested itself in horrible wars and the brutal and savage slaughter that followed. A decade of slaughter ended with the complete destruction of the planets population. However, the six priests managed to maintain a semblance of life as the Dark Side wraiths due to the dark side powers of the Altar.