The Scourge

The Scourge are a race of neuro-parasitic lifeforms that thrive on conquest and absorption of other sentient races. Their assimilation of the Cradle Worlds and Earth have made the Scourge the primary threat to humanity's existence, as well as showcasing the threat they pose to all life in the galaxy.

Of note, "Scourge" is the name given to the race by humans. What name they have for their species, if any, is unknown.

## Biology

Outside a host, Scourge parasites are boneless creatures with bodies made of a black, tarlike substance, surrounded by tendril-like extremities. In environments over .5Gs, a Scourge parasite cannot move outside a liquid, making "pure" Scourge unsuited to battlefields.

These creatures can survive for their full lifespan without a host, indicating that they may have evolved their neuro-parasitic abilities late in their species' development; however, only larval Scourge may successfully possess a host. These larval Scourge enter prospective hosts through the ear canal, burrowing through the soft tissues of the head before entering the brain, eventually binding to the spinal cord. Over the next several weeks, the Scourge parasite will develop into a web of gelatinous fibers bound to the host's nervous system as it learns how to use its host's body.

Though Scourge-controlled hosts appear normal at first, external characteristic swiftly develop that give their possession away - namely, a heightened thirst, coupled with constant sweating. Hosts lose the ability to produce colour pigment over time, causing their eyes to turn red and their skin to become pallid. Late in a Scourge parasite's lifespan, the skin of their host will begin to rupture, revealing black spikes of hardened material that may be the Scourge physically outgrowing its host.

Though humans are obviously favoured as hosts, the Scourge can infest a wide variety of carbon-based lifeforms, including the so-called "Lizard Warriors" seen during their original invasion, Razorworms, and Destroyers. "Pure" Scourge parasites that are past the larval stage are implanted directly into their various war machines, which they can control just as easily as a host (though some larger weapons require multiple parasites).

Scourge parasites prolong the lives of their hosts, though they themselves still age and can live for several centuries. Close to the end of their lifespans, Scourge will begin to lose control of their hosts, leading to erratic and jerky behavior. When the parasite dies, the host dies shortly afterwards, wracked with insanity and pain. Due to the disruptive nature of this process, most Scourge that exhibit these symptoms are euthanized by their fellows.

Currently, there is no way to remove a Scourge parasite safely from a host - any attempt to do so always results in the host's death. Horrifyingly enough, a measure of human consciousness survives underneath the Scourge's domination, leading the host to endure an existence of pain and suffering until their death. This explains the erratic behavior of late-stage Scourge - as the parasite's grip on its host weakens, the host's invariably-insane psyche begins to break through.

Scourge communicate via complex, highly-modulated, multi-spectra electromagnetic waves, which only works in close proximity to other Scourge. This method of "speech" can be interfered with, but only on the level of broadcasting loud noise to stop audible communications - impractical en mass. Scourge have demonstrated command of language, and can speak with humans if they choose to; however, this has only happen once in recorded history.

## Occupation

It is still unclear how the Scourge discovered humanity's central worlds, though some evidence points at Shaltari interference. Regardless of how it may have happened, on May 3rd, 2507, the Scourge descended on Earth and the Cradle Worlds in force, sweeping aside all resistance within hours. After subduing humanity's defenders, the Scourge turned their attention towards taking live prisoners, which may have contributed to many humans being able to flee. Despite this, only 1% of the Earth's and 5% of the Cradle World system's populations were able to escape to the colony worlds.

With humanity's military destroyed and population cowed, the Scourge turned their attention towards repurposing the industrial centers of their conquest for their own ends, which they augmented with their own organic-looking structures and run 24 hours a day. Vast breeding hives were also constructed, allowing the Scourge to replenish their losses and begin infesting the captured populace. As the supply of captured humans ran out, the Scourge also constructed cloning facilities in an attempt to produce bio-accelerated human hosts, though these endeavors have had poor success rates.

Crucially, over 160 years of occupation, the Scourge never disabled the foldspace nodes on the planets they conquered. It's possible that the Scourge were unable to locate where the nodes were hidden, or saw no reason to change the node codes. Either way, this would prove to be a crucial mistake, as the United Colonies of Mankind were able to use these nodes to return to their captured homeworlds.

## Reconquest

Though the Scourge were clearly unprepared for humanity to strike back, they have risen to the challenge of defending their holdings. The assaults on Olympus Prime and Earth have cost the UCM a large percentage of its available military strength, while not managing to completely destroy the Scourge navy. Meanwhile, on every Cradle World declared conquered by the UCM, the Scourge maintain pockets of resistance that continue to drain resources from their aggressors.

Despite this, the Scourge are beset on every side, confronting Shaltari actions on Aaru and PHR assaults in both the Asgard and the Tlalocan systems. The recent departure of half of the Scourge's Earth defence fleet may indicate another, as-of-yet unknown theater, against an unknown enemy, that they require significant forces for. Though the full strength of the Scourge military is unknown, their offer of a peace treaty to the UCM may indicate that they have nothing else beyond what is currently known.

## Leadership

How the Scourge are directed is still a complete mystery. Some sort of command and control system is theorized to be in place (given the speed at which they were able to conquer humanity's holdings), but so far there is little evidence for this. However, the immense amount of communications traffic that Scourge super-dreadnoughts maintain indicates that their leadership may be safely ensconced there, protected by the might of such powerful warships.

Though the UCM initially theorized that the Scourge had no individuals (an assumption made due to the single-mindedness with which individual Scourge serve their race), they have since encountered undeniably different characters whose behaviors are far outside the expected parameters. As a result, those that prominently display these characteristics are frequently selected to be leaders for the Scourge.

Though Scourge warships are controlled by a meld of Scourge parasites that serve as its 'soul,' they are frequently found commanded by a human-based Scourge host. This may indicate some kind of merit system that allows individual parasites to transcend their host's biological limitations.

## Military

Scourge armies are vast and formidable military machines that potentially exceed the manpower of the UCM in terms of troops. Crucially, human soldiers must volunteer to fight, whilst every Scourge ever born will serve their race until their death.

Most Scourge combat troops are made up of human hosts, many of which are the same individuals that were assimilated 160 years ago. The Scourge also employ a wide variety of more beastly hosts in combat, such as Razorworms, Destroyers, and Screamers, that were bred specifically to be used as shock troops. These more exotic forces are also deployed in scenarios where non-human body types are preferable.

Scourge ground armies are backed by a menagerie of organic-looking, technologically-advanced constructs, from grav-tank to looming walkers to hovering dropships. Larger, more outlandish war machines are also known, with their Annihilator and Desolator behemoths towering over the battlefield. These vehicles are controlled by Scourge parasites that have been melded with the machine - a practice considered second-best to taking a host, lending an extra edge of viciousness to their attacks.

The Scourge's navy is potentially the largest and most formidable in the galaxy, with thousands upon thousands of ships deployed across their various holdings. Most of these ships are old, their scars indicating that they were the exact same vessels that besieged Earth 160 years ago. By comparing these "newer" ships to the oldest in the fleet, it's possible that the most venerable Scourge vessels are over 1000 years old. Crucially, no full-sized Scourge ships are constructed anywhere in known space, leading the UCM to guess that they are only built in distant territories.

Though the Scourge are careful to never commit too many ships to one area, lest they leave an opening, the UCM have been able to exploit the spread nature of the Scourge navy to make significant headway in reconquering the Cradle Worlds. That said, the Scourge always fight to the last to protect their conquered systems - not a single vessel has ever fled for safe harbor elsewhere, instead opting for guerilla strikes or convoy raids against unsuspecting enemies.