Disclaimer: I don't own NieR: Automata, all rights to the owners
This little fic had two main inspirations. The first would be another fic, called "YoRHa Type-S: A Brief Chronology" which you can find on A03. I think it's fairly obvious, if you read it, how it inspired this fic. The second inspiration, oddly enough, is the clinical writing style of the SCP Foundation wiki. I didn't employ that fully here because an utterly clinical tone wouldn't be appropriate to this fic, but I wanted to employ aspects of it's unique fashion of storytelling.
Level 2 Clearance Required
Exterminator Series [X Model] Condensed History Document
Overview
The Exterminator line of androids and weapons is a relatively new addition to YoRHa forces, with the first experimental unit entering service in April of 11767. They are the first and currently only line to use microbots, and are the culmination of centuries of research and development into the field of nano and microrobotics. Two series are currently in service. The X6 series is highly niche and specializes in missions of extreme to theoretically infinite duration, and the Smart Exterminator Mark 7 deals in weakening enemy encampments before an assault, supporting ground forces, and operating in extreme conditions.
Rapid Assimilation Microbots - R.A.M
Rapid Assimilation Microbots (hereafter referred to as R.A.M) are multi-purpose machines designed for attaching inactive machinery to their host android through cutting, welding, and rewiring. They are additionally capable of field repairs and active modification of the host android and assimilated machinery. Two main subtypes exist: armored microbots, and unarmored microbots. Armored microbots are standard, and unarmored microbots are unique to the X6 series.
The first edition of Rapid Assimilation Microbots began testing in February of 11766 using Test Model B257*, a modern battler body (B82.017 Model) with the blackbox removed so all systems could be operated by the engineers. Test Model B257 has been informally redesignated "X0'' by engineers.
The initial test of R.A.M was an attempt to replace B257's left arm with a Goliath Biped arm using the R.A.M. The test was successful in attaching the Goliath Biped arm to B257 and synching it to their systems so that the engineers could control it through B257. With the success of the initial test more tests were rapidly approved and eventually a live test with a modified battler android was approved, resulting in an X1 model coming to active service a year and two months later.
*See B82.017 design documents and Rapid Assimilation Microbot test documents for more details on Test Model B257 and the Rapid Assimilation Microbots.
X1 Model [X38]
X38 was the first active prototype unit. The most notable change to her compared to X0 was the addition of standard android features. Like the test model, she had the body of a modern Battler line android (B82.054), though unlike the test model she was given a fully functional personality matrix with all the standard mental modifications for a Battler line android as well as being programmed with greater creativity to allow for flexible usage of R.A.M. X38 was assigned to a special squad specifically designed to support her so that her maximum effectiveness could be measured. This squad was officially called Squad EX, but was nicknamed "The Extermination Crew" by its members and associated Operators; a nickname which would carry over to the successor squad of X2 before the Exterminator line entered full production.
X38 proved to be an extremely effective fighter, though this was notably despite the abilities of her R.A.M as she was uncoordinated in the usage of assimilated non-android parts, and assimilation was used by X38 as a last resort rather than a primary method of combat. The only exception to this was the use of artillery, with which X38 proved oddly proficient. During one mission there occurred the first and only instance of R.A.M being used to fuse an android with a 250mm battleship howitzer.* The howitzer had suffered damage to its CPU and was inoperable on its own, and by linking her own CPU to the howitzer X38 was able to operate the weapon despite it's damaged state. From then on, X38 was known to fuse with artillery pieces whenever the chance presented itself. Overall, however, her assimilations tended to be tame and limited in scope. X38's affinity for artillery is thought to be a result of her personality, not an inherent bias of the R.A.M.
X38 suffered frequent logic virus infections as a result of her assimilations, and her chip capacity was expanded to maximum and loaded with anti-virus programs in an attempt to counter this. However, even her expanded capacity was insufficient for the most powerful anti-virus programs, and so she still occasionally suffered the virus despite her upgrades.
On account of the necessity to return X38's body to default between missions she had to undergo frequent repairs to remove assimilated parts and reinstall default Battler model body parts. Occasionally, if she assimilated a part too large, she was too large to enter Flight Units and the part had to be amputated on the surface so she could return to the Bunker. Most frequently this was the result of X38 assimilating Goliath Biped parts.
X38 was known for being emotional and easily scared, and was prone to bouts of hysteria, which is very non-standard for an android with a Battler personality matrix. She was also known to suffer emotional shutdowns which resulted in a severe decrease in performance. She did not get along well with most androids on account of her perceived cowardice and was on shaky terms with her own team for the majority of her active service.
Many lessons were learned from X38. When she was eventually killed in action during the Battle of Quebec, X2 was already nearing the end of the design phase and so it was decided X38 would not be rebuilt.
*Information on this mission requires level 4 access. If you do not possess that clearance level, please request temporary access to the mission documents from Commander White.
X2 Model [X2]
Physically, X2 was a modified Battler model. She was larger overall to accommodate greater internal memory banks and a more powerful CPU to hold and run the most powerful anti-virus programs available, as well as detachable limbs to ease the process of assimilating parts, and extra armor on the main body to prevent critical damage as assimilations had frequently rendered X38 slow and unable to avoid attacks.
X2's personality matrix was more well suited to their role. X2 was known to be aggressive to the point that she was sometimes called "suicidally reckless" by her teammates. Unlike X38 who had an unusual affinity for artillery pieces, X2 showed no particular specialty but was more competent overall in her use of R.A.M. She was, however, known to ignore the intended use of assimilated pieces in favor of using them as bludgeoning weapons. If she lacked an assimilated part, she was also known to try and assimilate still-active machines (to an unexpected degree of success) through the crude form of hacking her R.A.M were capable of.
Compared to the limited use of assimilation from X38, X2 used it as a proper secondary fighting method. Fully custom Exterminator series AI had not yet been developed, but X2's aggressive fighting style made far better use of assimilation than X38. However X2 was not particularly skilled in recognizing the best tool for the job in terms of assimilation, and most parts were used as crude replacements or temporary bludgeoning weapons.
X2 was responsible for pushing the boundaries of what R.A.M were capable of assimilating. She assimilated large objects such as a Flight Unit and an entire Goliath Tank. Improvements in the speed and power of R.A.M were started largely in response to X2's increasingly ambitious assimilations.
X2 was killed in action after assimilating a stubby head to replace her own damaged skull and being infected with a new strain of the logic virus that her anti-virus programs could not handle, which resulted in her going berserk and being put down by her squad.
X3 Model [X88]
Starting from X88 and onwards, Exterminator series units were given fully custom models and personality matrices. This included a transition from female units to male units, and the rest of the Exterminator series would be male due to their slightly increased power and the realization that Exterminators could work well alone given that their R.A.M could be utilized to their full potential. Until X3 the Exterminator series was not cost-effective, as producing R.A.M was both costly and time-consuming compared to the return on investment offered by their limited use.
X88's model was drastically different from X2, because the X3 were the first Exterminator series to be developed from scratch rather than being modified from another line. X88 was specifically designed to make use of R.A.M as his primary tool, and was heavily armored and bigger than even X2. This was to make way for a more powerful battery and extra R.A.M reserves designed to allow him to function for long periods of time on his own. Other long-term survival essentials like Recoveries and Mending Gel were deemed unnecessary as X88 could theoretically assimilate whatever he needed to replace damaged parts. The only irreplaceable parts of him were his blackbox and CPU, both of which were kept in his chest behind heavy armor. Unlike most androids, X88's head did not house his CPU as it was expected to be replaced during missions. All vital systems were kept in the chest.
X88 was eager, curious, a dedicated artist, and invented many inventive ways to kill machines. The practicality of his methods were debatable, but they usually worked and he reigned himself in when a situation was appropriately dire. X88 demonstrated the first instance of total replacement, in which all of his parts beyond his blackbox and CPU were replaced by assimilated parts.
X88 also brought to Command's attention what would become a recurring problem for the Exterminator series models: he suffered from acute mental and emotional distress as a result of his ever-changing body and the extended periods of solitude brought on by his assigned missions. He was known to be desperate for companionship when at the bunker, yet his over-eagerness to converse and near hysteria alienated those he sought out. He went through numerous memory wipes so he could be kept functional.
X88 was not killed in action. He requested he be withdrawn from active service once the first X4 model finished development, and the request was accepted as the X4 models were predicted to be significantly more efficient than him. X88 now serves as part of the morale team, using his artistic inclinations for the betterment of YoRHA.
X4 Models [See Designation List A]
X4s were the first Exterminator series to have more than one unit, though due to the high cost of producing R.A.M this only ever resulted in two hundred units being made, one one of which resides in the Bunker's deep storage for safekeeping.
A niche for the Exterminator series was finally discovered during the active time of the X4 series. Their ability to assimilate parts made them uniquely suited to the most long-term of missions, as unlike other android lines Exterminators did not need resupply drops as they could assimilate parts to replace damaged ones, and they functioned perfectly well without a squad.
This theory of usage was proven during an operation known as the Puerto Rico Trial, where a single X4 model was dropped on the island that was once Puerto Rico and tasked with eliminating all machine life there by himself. The single X4 model succeeded in his mission within three months, proving more cost effective than any android or weapon before it.
The X4 unit had no support during the Puerto Rico Trial, not even that of an Operator. It also displayed what would become characteristic of Exterminator models after long missions: highly specialized assimilations designed specifically for its environment. Researchers liken the process of an Exterminator gathering assimilations and finding the best ones for the job to biological evolution, except on a drastically smaller time frame.
X4 units deployed in primarily desert areas would create planks out of assimilated scrap to ski across the surface of the sand, sometimes with the assistance of a propeller on their back for propulsion, units deployed in the mountains would assimilate material to create heavily reinforced shocks and high-jump capabilities and/or claws capable of digging into stone, units deployed in mines would develop extremely potent close-quarters weapons and create a way to dig (often by using drills assimilated from small sphere-type machines). Full-body replacements became frequent, and at the end of a mission an X4 unit rarely resembled an android at all, or any of the standard machine types. Some of their forms ended up being very large as well, with one mission in particular resulting in the X4 unit assimilating several goliath tanks and becoming a mobile fortress nearly thirty meters long with five main cannons and more than a dozen secondary guns.
Mission failures were often a result of logic-virus infections, as while X4 anti-virus programs were the best around they were not able to counteract every strain all the time, and they encountered the logic virus more often than any other line of android.
X4 units were largely known for being calm and collected, if quite reserved, which perhaps contributed to their longevity. However, the psychological strain of their solo missions often eventually resulted in them developing bizarre quirks, coping mechanisms, and psychological disorders. During one routine check of all androids, it was recorded that there was a 64% personality disorder rate, a 40% post traumatic stress disorder rate, and a staggering 90% rate of frequent prolonged dissociation among X4 units. Several units were diagnosed with dissociative identity disorder, something thought impossible in androids at the time.
All X4 units underwent a mandatory memory reset after the check.
Even up to the use of the X6 models there were still some particularly skilled X4 units in active duty. By the time the Exterminator Mk 7 was produced, however, the last bodies of X4 units besides the one in storage had been killed in action, committed suicide, or gone MIA. It is estimated there could be at least ten X4 units still active in the world, though all of them are presumed berserk via logic virus and are to be killed on sight.
X5 Models [See Designation List B]
The X5 series boasted improvements in R.A.M technology as well as the implementation of new anti-virus breakthroughs. Upgraded R.A.M included an increased ability to construct and modify metal rather than simply assimilate parts as they were. The X5 also marked the first use of emotional inhibitors on an android, designed to curb the worst of the Exterminator series' tendency towards psychological disorders and severe emotional distress. As a result, X5 models were known to be awkward in conversation and had difficulty relating to others, and had muted reactions to the world around them. Their ability to understand metaphor and rhetorical devices was also inhibited, resulting in them taking things very literally.
The X5 models were only in production for two years, and only fifty units were ever produced due to an increased cost of production stemming from the cost of making the improved R.A.M and the complex emotional inhibitors implemented into the units.
The emotional inhibitors proved to be effective in curbing the Exterminator series' tendency for emotional distress and personality disorders. However, keeping the creativity required to make effective use of R.A.M and assimilations necessitated the emotional inhibitors still allow X5 units free thought, which resulted in X5 units frequently becoming frustrated with their own inability to fully feel emotions like other androids. Many requested their inhibitors be removed, though tests showed such a thing to be ultimately detrimental to their combat performance, and so inhibitor removal was forbidden.
With their improved R.A.M the X5 models were superior in capability to X4 models, though that gap could be significantly lessened by retrofitting X4 units with the new R.A.M (which happened to all remaining X4 units over time as they returned to the Bunker after missions, as well as implementing the anti-virus upgrades). Unlike the removal of emotional inhibitors, the installation of inhibitors in X4 models was allowed. Only a few X4s had inhibitors installed, and these X4 were redesignated as X4.5 models, with the difference between X4.5 and X5 models only being a few minor tweaks to the design of the model's body from small efficiency upgrades that reduced overall size and therefore production cost of the body.
X5 units, despite their upgraded R.A.M, did not demonstrate a massive performance improvement. There were some minor improvements, but it was quickly recognized that a reworking of their creativity circuits would be needed to accommodate the expanded abilities of the new R.A.M.. X5 and X4.5 units, while creative in that they were capable of reusing and amalgamating parts in innovative ways, struggled with more abstract thinking and designing new weapons or parts rather than simple repurposing, and failed to take full advantage of R.A.M construction and reshaping abilities. This would later be amended and hailed as the major improvement the X6 model had over its predecessors
X6 Models [X9, X24, X42, X57, X99]
Unlike other X series with multiple units produced, all X6 models were of the exact same physical model, that being the X6.352 body, with only minor aesthetic differences.
The X6 series is considered to be the pinnacle of Exterminator design despite it being the most niche of the entire Exterminator line, and perhaps of any YoRHa android model, due to its particular specialization. As a result, only five X6 units were ever produced. Like most Exterminators, the X6 series were skilled in long-term missions, but whereas most Exterminator missions lasted months or years, the X6 series specialized in missions of theoretically infinite duration.
The X6 series has a number of features unique to both the Exterminator line but also YoRHa androids as a whole. It is the only series to possess a duplicate blackbox as part of it's standard design. It also possessed even more powerful emotional inhibitors than the X5 series, but had increased abstract thinking and detailed knowledge of android, machine, vehicle, weapon, and armor designs and construction to allow for maximum flexibility in the usage of upgraded R.A.M. The X6 has the most slim base design for an Executioner unit to date, and unlike other units it forgoes a food and drink processor and various other human-emulation components entirely in exchange for efficiency. For this reason X6 units were often mistaken for S series androids, who they were intentionally designed to look like so their presence could be disguised if necessary. The X6 series also feature the most powerful anti-virus programs ever put in androids to date, and their anti-virus programs rival that of the Bunker itself.
The R.A.M of X6 models were also unique. They incorporated all the upgrades found in the X5 units, but forewent the armor the microbots usually possessed in favor of them being easy to produce. This is a direct result of the X6 series' other main design component: the X-200 Rapid Assimilation Microbot Mini Factory (often shortened to the X-200 MF). It was a metal cube twice the size of a blackbox that was capable of producing the weaker variant of R.A.M in the field provided the proper materials were inserted. This is what allowed X6 units to take theoretically infinite missions: as long as they could keep finding materials- which was a simple matter- they could replace destroyed microbots in the field which would in turn maintain the X6 unit. Until the X6, the only limiting factor of Exterminator series units was how long their microbots would last in the field. While microbots were resistant against heat, cold, EMP, and even explosions, they could still be eliminated by physical attacks either while doing an assimilation in combat or should the Exterminator's chest armor be breached and the attack damage the R.A.M holding chamber. The X6 remedied this by being able to produce microbots in the field, even if they were less durable. The microbots they made also included design plans so they could make another X-200 MF if necessary, as well as another blackbox given the right materials. This is why the X6 series always had two blackboxes: so they always had a spare should one be destroyed, and they could construct a new backup blackbox given sufficient time.
While X6 units were efficient for infinite missions, they were notably inefficient for moderate duration missions. Their frail microbots meant they often had to spend time gathering materials for creating replacements for those destroyed in combat and spending idle time waiting for them to be produced in the X-200 MF. For moderate duration missions the X5 series, or later the Mk 7, were heavily preferred.
X6 units were responsible for some of the most extreme forms an Exterminator model has ever taken, including the single largest form ever recorded, the most heavily armed, and the most heavily armored, along with some of the most bizarre and highly specialized.
Most of those titles are held by one particular form: a twenty story tall combat walker that numerous Operators and Scouts insisted was called a "mech".*
As a result of their powerful emotional inhibitors, X6 units were known to speak almost exclusively in monotone and had very little by way of personality. They did not socialize unless spoken to. However, each of the X6 models were known to have some minor interest in a hobby or activity, which is perhaps the only evidence of their free will noticeable to an outsider.
Though contact has not been made with any of them for seven months as of the time of writing this document, all five X6 units are to be presumed alive until proven otherwise. Their design is specifically tailored to make them all but impossible to kill and able to operate indefinitely, so it would be counter-intuitive to presume them dead from a mere lack of contact.
*Information on the details of the combat walker and the surrounding mission require level 5 access. If you do not possess that clearance level, please request temporary access to the documents from Commander White.
Smart Exterminator Mark 7 [See Production Number List A]
Originally called the X7 series, the Smart Exterminator Mark 7 (often shortened to the Mk 7) is the most recent design in the Exterminator series. After reviewing a proposal from several operators regarding the complete lack of personality and free will of X7 units, they were reclassified as Autonomous Weapons, and their designation was changed to reflect their new classification.
Unlike the X6 series, Mk 7s are currently the standard Exterminator units of the YoRHa forces, with the remaining X5 units relegated to special operations that require more intelligence to execute. Mk 7 R.A.M features a return to basics and design philosophy. Their R.A.M no longer feature the capability to create and modify parts like the X6 and X5, as it was deemed a superfluous feature. Exterminators were still perfectly capable of completing their missions by assimilating parts without modification. In fact, the Mk 7 was installed with fixed assimilation goals for various situations based off some of the most successful X5 forms, eliminating the need for creativity in the Mk 7 (and therefore resulting in the removal of increased creativity in the Mk 7, which also possibly contributed to their total lack of personality). Their R.A.M were otherwise based on the X5 design due to the increased durability of the microbots.
Mk 7 units are more efficient than X5 units and the most mass-produced. Unlike other Exterminator series units, they are sometimes deployed directly to combat zones for use in extended combat operations or as weapons to plant behind enemy lines to cause serious damage before the main YoRHa force comes in to clean up.
Command White has assured the rest of YoRHa that the Mk 7 is a special case, and that androids need not worry about being replaced by "simple mindless drones" as the intelligence of an android is much too valuable to casually discard. Yet the fact that the Mk 7s evolved from a gradual series of emotional inhibitions and still bear android bodies continues to trouble the minds of YoRHa soldiers, as they worry at the possibility that emotions being prohibited might truly begin to be enforced.
Make of this what you will. It's an experiment I've been trying to write for months, and at this point I just want it done and posted.
