The System Lords decreed it. Their will be done. Soon the Harvesters would come to reap their fill of those they felt worthy. Soon after the Ravagers would come and scour the planet clean. No one could know who would be selected and who would be purified in fire. The Harvesters were indiscriminate in their choosing. Theirs was an arcane selection. Strength and status meant nothing to them. They chose because they could.
As their sky-ships darken the planet, prayers are offered by some. Families say good bye and make peace with their gods. Some will fight. All who fight will be cleansed. The rest stand in congregation as the Harvesters make their selection.
No one will see the servants of the System Lords. It is not for the lowly to gaze upon their terrible visage. Those who are chosen, simply vanish as if they never existed. The only evidence of their passing are the wails of those left behind.
Cries rise up as family members disappear in columns of light. The Harvesting has begun. Woe be to those left behind. Your hour is at hand.
Praise be the System Lords!
--Cardinal Solifcant III, Deacon of the the Most Holy Lord Vs'ith. The Harvesting and Purification of Heretics. Vol. 1, verse 45.