The origins of the Obliterator Virus lie within the infamous Eye of Terror. Following the Horus Heresy, Space Marine and Imperial Guard traitors fled to the protection of the Eye, and there met with several virulent plagues never before encountered in the Materium. The most likely culprit amongst these plagues is the widely-known Nurgle's Rot, famed amongst the Death Guard. However, Chief Apothecary of the Emperor's Children, Fabius Bile, also experimented on various pathogens, viruses, and plagues, measuring the effect of the Warp upon their biological structures - meaning the Obliterator Virus might very well be a result of Bile's handiwork.
The Obliterator Virus consumes its victim in nine distinct stages, ranging from simple carriage to total absorption. Most carriers do not realize they are infected until it is too late for aid. Since the Virus takes an extended period of time to mutate and bond with its host, the creation of a fully-fledged Obliterator is time consuming and severely limits their numbers. The single exception to this rule rests with the secrets of the Iron Warriors, where Obliterators are both far more prolific and able to control the rampant mutations throughout their bodies. It is rumored that, in order to increase their number of battle-ready Obliterators, the Warsmiths of the Iron Warriors may be infecting specific warriors with the Obliterator Virus (perhaps even at the behest of Perturabo).
It has been proven that the Iron Warriors do intentionally infect certain people with the virus, using an altered version of it. Whether or not it is used to create more Obliterators is unknown, nor is it confirmed that the Iron Warriors were the ones to alter it.
Within the Imperium, mounting evidence suggests that the Obliterator Virus is active on worlds scorched by the wake of Abaddon the Despoiler's 13th Black Crusade and is in the process of spreading throughout the Imperium. Though the Virus can only spread at a fraction of its normal strength in the Materium, on worlds of sufficient numbers the threat of Obliterator Cults is growing.
Nature of the Virus
The virus is transmitted by the transfer of bodily fluids or simply by touch. Generally, the longer a person is in contact with an Obliterator, the more chance they have of becoming infected. The nine stages of infection and mutation differ in length between all people and depends mainly on whether the carrier is aware and resisting the spread of the virus. On the other hand, the infection is much more rapid in those that welcome such a virus, although the numbers of these people are surely small.
Stages of Infection
The infection comes in nine stages, leading from simple carriage to total absorption and the creation of a fully fledged Obliterator. The stages are:
No obvious effects but the victim is a carrier and can spread the disease to others.
The carrier now finds themselves to be more at home with weapons, his aim increases and the gun sits more naturally in his hands.
The carrier, finds themselves merging with their weaponry if they hold it for long enough. They also start to generate ammunition for the weapon they are holding, a most disturbing development.
The victim is now in the very throes of Obliteratorhood, with their armour no longer being able to be removed and seems to be able to repair itself. They also find their movement to be impaired and their joints rearrange and meld with the metal of their armour and weapons.
By now, the victim finds they can absorb small weapons such as knives and pistols and then recreate them at their own will, but only in small numbers at a time. Their sanity is also impaired by now.
The victims' very flesh is now made into a daemonic melding of metal and skin which adds to their armour and allows the absorption of many more complex weapons. They no longer look like humans as their body has bulged in places where weapons have been absorbed.
The body increases in strength and fortitude in an attempt to counter the ever increasing weight of the body. This makes them terrifying opponents in close combat.
The victim can now create things other than weapons, including bionic limbs and organs. Their original body flesh and daemonic metal are no longer distinguishable.
The final stage sees the creature as a fully fledged Obliterator and can use the heaviest of weapons in order to destroy its enemies.