Cryptosis

"It's the sight, not the bite, that kills you."

- Unknown

Cryptosis is both an infection and subsequent state of mind that has been recorded to cause those afflicted to witness the phenomenon of "invisible killers" in the form of Eldritch Abominations. It has both a solid, powder-like form as well as an airborne form. When beings are exposed to the airborne form, it takes an hour for the infection to develop, with the effects intensifying every other hour. The powdered form's effects are much more immediate when ingested or inhaled, and tends to yield more drastic results.

The infection itself attacks the nervous system, granting the afflicted a heightened sense of spatial awarness, allowing the mind's eye to essentially conceive what may have been once inconceivable. Despite whatever positive implications this may have at first, the infection and the state of mind it subsequently induces reacts only to positive feedback caused by negative stimuli registered by corresponding sensory information.

In more base terms, Cryptosis' more adverse effects come in the form of violent hallucinations registered by the mind in response to real though "invisible" threats to an affected person's existence. For example, should a person performing a space walk while under the influence of Cryptosis become subjected to the vacuum of space, they will literally "see" space killing them as they experience the checklist of ebullism, hypoxia, hypocapnia, decompression sickness, extreme temperature variation, and cellular mutation and destruction. The degree of damage recieved depends on the contraction of the infection - if the Cryptosis is ingested or inhaled via its powdered form, the resultant trauma will cover external and internal injuries; whereas damage via airborne contraction registers largely as internal, with the brunt of the damage reported to center around the nervous system.

History
The infection was first created in powdered form by ancient Shamans originating from an undesignated universe. It was originally a hallucinogenic drug said to provide a means to encounter and interact with the spirit world for any who ingested it. It would at some point be carried over into the OmniVerse by the OMS Revenant; and as a result of the relative impossibility of hyperspace travel, let alone travel between separate realities, mutated into its currently known state.

The Cryptosis infection would then go on to affect the Revenant's entire crew, contributing to the systematic slaughter of everyone aboard. The Revenant would then go on to traverse hyperspace for eons until reverting back to realspace on the fringes of Dead Space, where it would be discovered by the Asculum Strike Group...