While they don't use a rank structure, there are a variety of types and Combat Forms. This powder was actually Precursor remains. The earliest known instance of the highly infectious viral super cell later known as The Flood form to be encountered came in a fine desiccated powder, contained in cylinders. They were first encountered in the Milky Way galaxy by an Ancient Human empire 10,000 years prior to the Forerunner-Flood war. The Flood are an extremely adaptable, dangerous, and expendable parasitic life form.
