Reaper

Introduction
The Reapers are a highly advanced machine race of synthetic-organic starships. The Reapers reside in dark space, the vast, mostly starless space between galaxies. They hibernate there, dormant for 50-thousand years at a time, before they are given the signal to return. The Reapers claim that they have neither beginning nor end. Even their true name is a mystery; "Reapers" was a name bestowed by the Protheans.

The Reapers were the original creators of the Citadel and the Mass Relay network. These massive constructs exist so that any intelligent life in the galaxy would eventually discover them and base their technology upon them – all part of a scheme to harvest the galaxy’s sentient life in a repeating cycle of purges that has continued relentlessly over countless millennia.

Design
Reapers are shown to all share this basic design, but with great diversity in limb number, shape and orientation, some with extended heads and others having multiple glowing lights. All Reapers bear a superficial resemblance to a cuttlefish or squid, with a bulky semi-cylindrical body, a tapering plate over the rear and five tentacle-like "legs" or arms extending from its front end, in addition to six jointed legs extending from its body. The rear-most of the larger legs have crescent-shaped extensions. Reapers also have numerous small tubes that can extend from their underside; attaching these tubes to the structures or opponents during attack.

Subtypes
There are several varieties of Reaper, which vary significantly in size, purpose and firepower. The most well-known subtype are the two-kilometer long capital ship Reapers. Capital Ships are armed with multiple magneto-hydrodynamic cannons capable of shearing through most opposing vessels, and are also capable of unleashing swarms of Oculi to engage fighter-sized craft.

In addition to Reapers on the scale of capital ships, there is a subtype of Reaper known as the Destroyer. Destroyers are only 160-meters in height, considerably smaller than the two kilometers that Sovereign boasted, but possess a formidable capacity for destruction despite their reduced stature. Unlike capital ship Reapers, they have four main legs, along with five jointed appendages encircling their "head". The frontal plates of a Destroyer can fold to the sides, exposing a powerful beam weapon.

Other subtypes of Reapers include Troop Transports and Processors, both of which lack sentience and are instead remotely controlled by other Reapers. Troop Transports vary in length between 200-meters and one kilometer and are used to transport Husks to unconquered worlds and bring victims to Reaper processing centers. Processors are mobile centers for mass DNA harvesting.

Reproduction
The core of any Reaper is constructed in the image of the species that was harvested to create it, while the exterior follows a standardized design that is most efficient for their purpose. While the outward appearance varies between subtypes, all of them resemble the physical appearance of the Leviathans, the race that dominated the galaxy in the time before the Reapers.

A Reaper is essentially billions of organic minds, uploaded and conjoined within immortal machine bodies.

Indoctrination
Reapers and their technology have been observed to exert a disturbing influence on organic beings. This mental manipulation is known as indoctrination. Put simply, any organic being who is in close proximity to a Reaper or certain Reaper artifacts for too long comes to believe the Reapers are correct in their goals, and will do anything to serve them.

Gradually, the mind is eroded until the individual becomes a mindless slave no longer capable of independent thought. This indoctrination is permanent without extensive and long-term telepathic therapy and is one of the most insidious weapons of the Reapers. Entire civilizations can be delivered into the Reapers' hands by the indoctrination of a few influential individuals.

Even more horrifying is that the indoctrination field remains active even if the Reaper is largely disabled and incapable of action.

A Reaper can control the rate of this process, in order to serve the Reapers efficiently, as some puppets will need a measure of free will to accomplish lengthy missions.

Only beings of immense mental strength, such as Asari and Betazoid matriarchs or Vulcan priests, can resist indoctrination, and even then, their resistance only lasts a short time and only forestalls the inevitable.

Technol​ogy
Even without their indoctrinating influence, Reapers are immensely powerful warships and their technology is devastating, with destructive power unrivaled in the known galaxy.

Each of the "tentacles" extending from its bow was equipped with a powerful "magneto-hydrodynamic" weapon which ejects a stream of molten metal at a fraction of the speed of light which could tear through a cruiser in a single sustained burst. Its gigantic spinal-mounted gun was able to rip through the hulls of even the largest of dreadnought-class ships with ease, effortlessly penetrating their shields. Defences included powerful shields that could block the projectiles of an entire fleet, along with an incredibly strong hull.

Though they are sentient machines, the Reapers have habitable interiors that can transport a crew, either to help spread their indoctrinated slaves and to allow these slaves to tend to them. Each individual Reaper has a massive element zero core which, coupled with the likely enormous quantities of energies at its disposal, allows it to generate the staggering mass effect field needed to land on a planet.

However, the Reapers are not invincible. When the Reapers go into states of hibernation between cycles, they are vulnerable. By taking refuge in dark space, the Reapers ensure they will not be discovered by accident and destroyed while they wait for their vanguard to open the Citadel Mass Relay. A concentrated effort by the fleets of organic races could also destroy a Reaper even if it is at full power.

Aside from their formidable firepower and indoctrination, Reapers are also capable of mustering up their own ground forces to attack their enemies: husks. Husks are aggressive, mindless drones, created from organic beings who are exposed to Reaper technology, such as dragon's teeth, resulting in their organic bodies being consumed by cybernetics. Husks are used as shock troops and swarm enemies in waves. Occasionally, to bolster husk defenses the Reapers will employ devices known as Barrier Engines that cocoon individual husks in a durable biotic barrier.

Harvesting
During their invasion at the end of each cycle, the Reapers gather and "process" vast numbers of individuals from each of the galaxy's sentient space-faring races. Victims who cooperate with or are captured by Reaper husks are rounded up into "camps," where the husks select individuals deemed fit for processing; it is believed that the husks use scent or chemical receptors to analyze the genetic composition of victims. Those who are deemed unsuitable are turned into more husks.

Individuals who are determined to be suitable for processing are loaded onto Reaper Processors, where they are ushered into single-person pods. Like a slaughterhouse, the interior of the Processor is designed to prevent any visual or auditory contact between individuals being processed. Once in the pods, the victims are dissolved into a raw genetic "paste" for ease of transport. This paste will then be used in the construction of a newborn Reaper, with the victims' minds being preserved to form the Reaper's gestalt consciousness. The only known facilities used for Reaper construction are located on the Citadel and within the Collector Base in the galactic core.

Available information suggests that a single race is harvested during each cycle to produce Reaper Capital Ships; it appears that other space-faring races harvested during the cycle are used to produce Destroyer-class Reapers. Exactly how or why this distinction is made is unknown.

Birth
5.3-billion years ago the ancient race called only the Preservers began to expand out into the galaxy, but found little in the way of life. Seeking to counter this they triggered life on thousands of world and soon began to interact with these new younger races, including those that would become known as the Reapers, the Walkers of Sigma-957 and all the other races that would one day be collectively called 'the First Ones'. The Preserver race helped them to develop and nurtured them, acting as their teachers and guardians. Eventually Preservers stepped aside and allow these new races to stand on their own and over the eons eventually becoming the teachers and guardians of the younger races as they begin to arise.

Schism & Banishment
Until 1.5-billion years ago this cycle was very successfuly, which each generation nurturing the next as the Preservers watched. However when the Preservers decided to leave the galaxy, in order to explore the expanding cosmos and begin new cycles across the universe, a shism appeared among the First Ones and what consituted the best evolutionary apex to match the Preservers.

Many First Ones supported the traditional view of the Preserver Cycle, to terraform new worlds, trigger new races, nurture them until they could be left independent, then retreat as their 'children' began the cycle anew. However radical ideas began to appear, ranging from the Walkers of Sigma-957 supporting an eventual digitial evolution of races, to the Undian who supported assimilitation and inbreeding with their evolved charges to create a diverse yet 'perfect' evolution.

The First Ones known only as the Reapers began an attempt to uplift not only their kind but their charges beyond the mortal humaniod body, which they saw as weak and deeply flawed. Melting their enitre species down into its raw organic matter and recombining it into massive space going bodies, they uploaded trillions of minds into these bio-mechanical bodies to become unbound to their psychical forms, able to explore the galaxy like never before.

Ironically many other First Ones applauded this ingenius evolution and some even attempted to emulate to lesser degrees.

However in less than a 100-million years, the Reapers began to become 'cold' or 'arrogant' to their First One counterparts, and especially to the younger races. They began to see their bio-mechianical evolution to be the only true apex to the Preservers and while they offered to extend this new state of being to all, they refused to accept rejection by others. The Reapers forced evolved other races whether they accepted it or not.

In order to facilitate their invasion of other races, the Reapers develop their most indious technology. Indoctrination. Any organic being who was in close proximity to a Reaper or certain Reaper artifacts for too long began to believe the Reapers were correct in their goals, and would do anything to serve them. The Reapers used this as justification when they took worlds from other First Ones. However long-term observations soon discovered that gradually, the minds of Indoctrinated individuals eroded until the they became a mindless slave no longer capable of independent thought.

Almost one-billion years ago, after destroying a thousand worlds and processing trillions of beings into new Reapers, the Reapers were tricked by other First Ones into the event horizon of a black hole. In order to escape, the First Ones projected a gateway on Beta Durani VII to dark space, the starless voids between galaxies. Projecting the gateway as the only escape from being crushed by the blackhole, the Reapers were forced into dark space and banished from the galaxy.

Without an ability to reproduce, feed themselves or repair damage, the entire Reaper species collectively entered hibernation to await a time they can return to the galaxy.

Escape & Harbinger's Plan
Close to 450-million years ago,the gateway on Beta Durani VII was accidentally opened, allowing the Reapers to re-enter the galaxy. As most of the First Ones had retreated to explore the universe much like their Preserver forefathers, the Reapers met no resistance. They quickly set about consuming much of the galaxy for resources and new races to uplift into Reaper forms.

However in a short millennia they rendered all sentient life extinct in the Milky Way and with resources sarce and much of the galaxy devoid of all organic life fighting erupted between the Reapers. After much of their own race was decimated a single Reaper known as Harbinger formulated a method of survival and convinced the remaining 75 Reapers to his ideals. He knew that the galaxy would never be able to constantly sustain their kind, so he proposed a plan of long hibernation to allow the cosmos to rebuild before returning to harvest for resources and new races to uplift.

The Reapers seeded the galaxy with Mass Relays, with the intent that sentient species would develop FTL drive, but would still be limited in its speed. By leaving a network of relays capable of instant transport across the galaxy that led to the impressive Citadel, the Reapers ensured that it would become the center of galactic civilization. Further, the presence of the Mass Relays would lead the sentient species down a predetermined route with regards to weapons and armor technology. It is probable that this reduces the possibility of organic life discovering alternative, more advanced technology and progressing down a different 'path'.

The Reapers construct the Citadel with the intention that once the sentient races have established themselves on the Citadel with the aid of the keepers, who copy census data until the galactic population has grown to a level able to not only sustain the Reapers, but allow them to reproduce, the vanguard sends a signal to the Citadel, instructing the keepers to activate the station’s hidden mass relay. This opened a path between the Citadel and dark space. The Reapers would pour through, killing the leaders of the assembled species before branching out and obliterating all spacefaring life around them. Because the Reapers first enter the galaxy at the point that they have ensured will be the center of galactic politics, information and finance, they are able to cripple any resistance almost before the Citadel civilizations have any idea that they are under attack. The Citadel also gave them control of the relay network, cutting off star systems from each other and destroying communications.

The Reapers then would use their control of the Citadel and its data to begin the most sinister phase of their attack. Records allow them to track down every settled planet and attack them, either stripping the worlds of resources or enslaving the populations with Indoctrination and turning them into sleeper agents. The Reapers continue their cycle, in which all the sentient life in the galaxy is harvested and melted down into bio-mechnical Reaper shells based on the individual species' physical form.

Cycle of Extinction
Around 448,948,000 B.C.E. the Reapers launched their first culling of the galaxy. After difficulties during the first incursion with the younger races being just strong enough to put up a true and concentrated fight, the Reapers decided to leave behind a custodial species to maintain the Citadel and as a key to the Reaper genocide. Programming these keepers of the Citadel, they were left to monitor when a civilization was judged to be sufficiently advanced. Using their first conquered victims, the Om'lac, the Keepers were created by the Reapers. Whatever their origins, the main purpose of the keepers now is to maintain the Citadel in its attractive state so that sentient organic life would settle there, and support their habitation of the Citadel once they touch possession of the station. However, once an organic species has settled on the Citadel and reached the required level of technological advancement, the Reapers' current vanguards, several Reapers left behind to monitor the situation, would sends a signal to the keepers compelling them to activate the Citadel relay to dark space, and begin the process of genocide.

Every 50-thousand years, the Reapers would continue this cycle, wiping out thousands upon thousands of races who feel victim to the trap which using their resources, people and sometimes even their technology to create more Reapers. However sometimes culling cycles did not go as planned.

250-million years ago, the dominate younger race of the time, the Manraloth, built a working inter-dimensional logopathic conduit that could be directly interfaced into the Manraloth brain, intent on bringing about an instant galaxy-wide information and communication network connect via people. Each device would be activated simultaneously in a great celebration across the galaxy but when the power of the higher planes poured into every brain connected to them and the Manraloth are able to perceive all of reality, within seconds quickly discovered the Reapers dwelling in dark space and Reapers were alerted that for the first time in their history their place in dark space had been discovered. As the Reapers began to move in for their culling, the Manraloth collectively confirm their intentions and designs for the invasion, while also coming to the conclusion they can not win a war with the Reapers based on their current technology, infrastructure and fleets. Knowing the Reapers need them for food and reproduction, the Manraloth and their allies willfully destroy themselves in mass suicide, having the surfaces of all their worlds reduced to ashes due to the heat and radiation generated by the forced incineration of their inhabitants. A galaxy of over a quadrillion individuals was depopulated in a matter of minutes after their greatest technological achievement. The Reapers, without being able to resupply themselves following such a disaster, end up cannibalizing one-eighth their fleet to survive to the next culling, an act they have never totally recovered from.

One-million years ago, the Chodak Empire, noted as being an one of the most highly advanced civilization in the entire galaxy, rose to its height and at the pinnacle of their power developed a subscape manipulation weapon called the Unity Device. The device was built in the process of 1650 years, for purposes were somewhat administrative; the Chodak government used it to control their far flung Empire, as well as occasionally using its awesome power to serve a military end. This massive machine had near unlimited power and was used to maintain the Chodak Empire's hold on power but the mighty empire collapsed when the Unity Device was destroyed by a Reaper invasion, leaving the Chodak largely defenseless. The Unity Device's main weapon was soon repuposed by the Reapers, greatly advancing their mass effect fields to allow them to travel as near unrivaled speeds.

In 600,000 B.C.E., the Arret explored the galaxy and colonized several planets, possibly including Vulcan. They achieved such great mental power that they began to regard themselves as gods. However the Reaper invasion tore the atmosphere from their planet, ultimately extinguishing all life save for a relative handful of representatives. Again according to one of their survivors Sargon, 'only the best minds were chosen to survive.' Those chosen transfered their consciousness into receptacles in a cave constructed 112.37 miles beneath the surface of the planet. From here, he carried out the task of probing the heavens for starships representing a race advanced enough to save his people from oblivion and to defeat the Reapers. The remaining dozen or so of his peoples' receptacles occupied niches in a smaller side chamber.

Around 370,000 B.C.E., an unknown spacefaring race fired a mass accelerator round at a Reaper near the planet Mnemosyne. The round penetrates the Reaper, disabling it, and continued moving through space, eventually striking the planet Klendagon and creating the geological feature there known as the Great Rift Valley.

Human/Forerunner-Reaper War
200-thousand years ago, the First Human Empire encountered evidence of the Reapers return in approximately 110,000 B.C.E. and, after discovering the machine's true nature, began to rapidly prepare for the coming conflict. However indoctinated Humans used by the Reaper Pontent ignited a civil war and after losing many planets, Humanity desperately invaded a minor sector of the Forerunners' domain to suppliment the lose of their major agricultural worlds. After forty-thousand years of expansion, the collective human genus waged war with the biologically-similar Forerunner species.

Eventually, they developed a cure against Indoctrination, winning the Human Civil War. Because Pontent had never encountered a race that could develop a cure to Indoctrination, it had to destroy the First Human Empire at all cost. In order to do this it covertly funded fringe purist groups to take control of the empire and spark a war with the Forerunner Empire.

However, the Forerunner victory proved disastrous for the galaxy, as the Humans destroyed all their research data and physical evidence concerning the Reapers, including the cure to stop the Indoctrination. Many speculated it was Humanity's final act of revenge to leave the Forerunners unprepared to face the incoming threat that led to the firing of the Halo array.

When the Reapers invaded the Forerunners, the resultant devastation was immense. In barely a century the Forerunner Empire fell and in the final hours of the war, the Forerunners realize that activating their last resort, the Halo Array, was the only way to stop the Reapers from overrunning the galaxy. The Halo pulse killed all sentient life within three radii of the galactic center, including any Forerunners not located on The Ark or within Shield Worlds. With only 1/10 of the galaxy successfully consumed before they ran out of biological sentients, the Reapers were forced to retreat into Dark Space.

Prothean-Reaper War
Around 48,160 B.C.E., the Reapers invaded the Prothean Empire, the dominate galaxy spanning civilization of the time. Even though the Protheans already knew of the Reapers, they were nonetheless caught completely off-guard by the scale and rapidity of the Reaper assault on their empire. The Reapers entered the galaxy through the Citadel, instantly decapitating the Protheans' government and disrupting the Mass Relay network, isolating Prothean systems from one another. Worse, records on the Citadel provided the Reapers with access to all of the Protheans' census data and star charts, allowing them to effectively track every Prothean in the galaxy.

The Protheans' greatest strength, their unified empire, proved to be their downfall. As the Protheans were united under the leadership of a single governing species with a series of subordinate races, the Reapers were able to quickly undermine the Prothean hierarchy and cause Prothean forces to become scattered when their ruling body had been compromised. On top of that, as all the races within the Empire conformed to a single military doctrine they proved unable to adapt and compensate for when the Reapers identified and exploited their weaknesses. Over the next several centuries, the Protheans would fight the Reapers from system to system, world to world, and city to city. If necessary, whole colonies were sacrificed and abandoned to the Reapers; while the Reapers concentrated on subsuming the inhabitants of those colonies, the Protheans had time to regroup. In the long run, however, this strategy was extremely costly, depriving the remaining Protheans of whatever infrastructure and manpower they had given up. Inexorably, the Reapers conquered, enslaved, or destroyed Prothean-controlled planets.

When the Prothean-Reaper War began to drag on longer than the Reapers had intended, they resorted to cloning indoctrinated Protheans to compensate. After several cloned generations led to increasingly erratic, weak or mutated Protheans, the Reapers eventually decided to genetically rewrite these Protheans altogether. These captives were transformed into an entirely new race which cooperated with the Reapers and would eventually be known to the contemporary galaxy as the Collectors. After centuries of careful, systematic work, the Reapers had killed or enslaved every Prothean in the galaxy, and stripped their worlds of resources. Removing all traces of their presence, the Reapers then retreated through the Citadel into dark space and sealed it behind them.

Reaper Folly and Prothean Legacy
As thorough as they were, however, the Reapers had overlooked a several worlds, either due to accident or misinformation.

The Conduit research team on Ilos, of which all records were destroyed in the initial attack on the Citadel, survived the first wave of destruction. The facility went dark in order to avoid detection and the staff agreed to go into stasis, hoping the danger would soon pass. Vigil, a VI, was assigned to watch over these Protheans in cryogenic stasis until the Reapers had gone, then wake the staff so they could begin to rebuild. But as the centuries passed and the Reapers persisted in their genocide of the Protheans, Vigil's power supplies began running low, and the cryo pods were in danger of failing. Following contingency planning, Vigil began cutting power to the pods of non-essential staff to conserve energy.

When the Reapers finally withdrew through the Citadel relay, only the top researchers — a dozen individuals — were left. Vigil woke them, and the scientists pieced together what had happened. They soon realised the situation was dire. Without sufficient numbers to sustain a viable population, the Prothean species was doomed. Desperate for contact with others of their kind, a carefully-coded signal was sent to the beacons on other planets. Though it was unlikely there were other survivors, the scientists thought it was worth the risk to try reaching them. The signal not only contained a warning of the Reaper invasion, but a description of Ilos itself, to give them hope. The surviving Prothean scientists knew that rescue was unlikely. Instead, they chose to protect the races they had been studying, spared destruction due to their lack of advancement, and began working out where the Reapers had come from, and how. After decades of study, they worked out the connection between the Reapers, the Citadel, and the Keepers, and discovered a way to interfere with the signal that compels the Keepers to activate the Citadel relay. Using the Conduit, the Prothean scientists left Ilos, travelled to the Citadel and altered this signal. Their intention was to prevent the Reapers from opening the Citadel relay again, and trap them in dark space, but they had no way to be certain their plan had succeeded.

Current Era
The contemporary era will be 9012th Reaper culling to date. Currently there are six known Reaper Vanguards in the Milky Way, though the exact number could be more.
 * Sovereign
 * Monarch
 * Herald
 * Presage
 * Regent
 * Prophet