Vainaja
The result of the Reaper Virus - Namely, the reanimation of corpses, which attack the living. These undead corpses are referred to as the Vainaja.
There are similar to the Svamganger - the key difference being, the Svampganger are infected individuals who are still alive, whereas the Vainaja are outright dead, and reanimated by the Reaper Virus.
They are the result of an individual infected by the Reaper Virus coming dying. The exact method does not matter, so long as the individual is infected by the virus. If so, their corpse will reanimate, unless the brain itself is destroyed. They are
The types of Vainaja can vary between Void Islands, and even parts of the same Void Island, as the Reaper Virus is incredibly adaptable and prone to mutation. It has demonstrated an ability to survive in the most hostile of conditions, including the inhospitable Voidsea. Some strains break out, and the reanimated corpses rot away within a few months, leaving them a non-threat. Others can somehow sustain the body for a far longer period of time, preventing necrosis and rot, if not indefinitely, than for a longer period of time.
Vainaja outbreaks have been known to collapse entire worlds, even those deep within the territory of a Faction. Depending on the Faction, and the many factors that surround it, a world can collapse to the Vainaja before anyone even notices. Worlds that undergo collapse by Vainaja can be reclaimed, but it does require a commitment of resources. Sometimes, a world is simply left to the Vainaja, due to a variety of logistical and economic issues, or simply because it is easier to allow the Vainaja to rot away before reclaiming the world. Survivors may or may not be located - It depends if the Faction in question is willing to spend the resources to evacuate them.
The risk of spreading between worlds is cause for major concern for most Factions, which undertake extensive care to ensure no Voidship coming from an infected area contains the virus. Viral scans are undertaken on dedicated contamination stations, and decontamination protocols are strictly adhered to. Failure to comply with such procedures usually results in termination.
Some Factions have been known to use the Reaper Virus, and subsequent Vainaja outbreak, as a tool to weaken their enemies. As a consequence, many Factions regularly scour their borders, checking anything that passes over. this can drain their resources elsewhere.
Worlds that have a Vainaja presence are classified as Infected Worlds. Worlds that have collapsed due to Vainaja are known as Undead Worlds.
Discovery
Different Factions have encountered Vainaja in different ways.
For the Cosmic Union, it was first discovered on the Void Island of Izake, the homeworld of the Cherra-Zendir Kinde. When a Cherra-Zendir died, their corpse would reanimate, without exception. for a while, it was beleived that this was a process unique to the Cherra-Zendir, as it was not observed in any other Kinde, and the Cherra-Zendir themselves could not recall a time without the virus.
However, it soon became apparent that the virus was not unique to them, as it could infect other Kindes as well, and the virus that caused it could be transfered via other methods, including remaining dormant on the side of a Voidship until it made contact with another object.