Editing Cyfecti (section)

===Physiology===
Little is known of their physiology as no intact specimen has ever been retrieved to date, as upon the death of their brain the body bizarrely explodes in a cloud of plasma dust. While non-lethal, the plasma dust-cloud is dangerous due to its toxicity, but is generally diffuse enough in a ventilated area to only cause severe irritation if inhaled. Also unexplained is the small crystal-like stone that appears in the same process that creates the plasma dust cloud.
This is believed to be due to obscure rituals that bind the physical body of a Cyfecti specimen to the warp somehow.
This means everything we do know is based on inductive and deductive reasoning derived from conjecture and observation, or from documentation from other xenos races, such as the Eldar.

The Cyfecti appear to naturally possess very high-level Psyker powers, with some individual Cyfecti believed to have powers that exceed Imperial psy-level classifications.
Presumably, their corruption by the Ruinous Powers has increased these levels beyond their natural limits, and it is perhaps then fortunate that so few Cyfecti existed during the Heresy, and even fewer exist now.