The Neuroi (ネウロイ) are the primary antagonists of the Strike Witches. They are a belligerent alien race that appears every so often. They literally consume swaths of the earth to gain their power, Europe and Africa being the most affected continents. Since they derive much of their energy from consuming land, they can not travel over large bodies of water.
It's of note that humanity gives names to the Neuroi depending on the class and role they fulfill or due to the nature or features of the class in question, as shown in the Witches of Africa Doujinshi and the Misfits Light Novels. For some Neuroi classes are given Latin sounding names of origin like Diomedia, Laro's and Laro's-kai or names based on the shapes, actions, attributes or nature such as the Flying Goblets, Ziggurats and Turtle class. Even Infantry class Neuroi have been observed in the field.
They are also further identified through class type depending on their function: Recon types (Neuroi dedicated to reconnaissance roles), Attack Types (Neuroi designed primarily for attack roles and direct warfare), and Siege Types (massive-sized, formidable Neuroi that are designed to either remain in place, to serve as a mobile fortress to defend Neuroi territory, or to serve as a juggernaut to steamroll through allied lines), although other general role classifications like Artillery Types, AA Types and other such Neuroi role fillers may also exist.
Most highly common classes are given such names. Unique Neuroi classes, however, receive an alphanumeric designation of "X" followed by a number, likely indicating the order in which those Neuroi are encountered by the 1940s. The X-11 Witch class Neuroi is one such example. Some other unique Neuroi units and their respective drones and supplementary satellite units have also been recorded and identified as "OX" in addition to the numerical identification number.
Throughout history, the Neuroi have been known by many names - including Kaii (怪異, strangeness) and Rätsel (German; riddle). However, starting from the Second Neuroi War, they received the name of a mythical tribe that once lived in the Black Sea region due to their recurrent emergence from that area.
The first known contact between humans and Neuroi occurred when ancient Egypt was at the height of its glory. It is unknown what preceded this, but humans were able to seal a nest of Neuroi beneath a city. They struck the name of the city from history, as even knowing of the seal would cause it to break. When these Neuroi were inadvertently released during the Second Neuroi War, their models were revealed to be identical to the models of Neuroi already fighting in the area. The reason for this fact is unknown, but it possibly implies that the Neuroi didn't develop technologically until the Second Neuroi War forced them to do so.
The Neuroi appeared sporadically throughout human history after this point of initial first appearance at ancient Egypt's height, but they never posed a serious threat until after the invention of the magic engine, a steam-powered device which amplified a witch's magic ability many times, and the resultant rise in magic usage. The first wave of Neuroi attacks culminated in the First Neuroi War, which lasted until 1917 and was a massive victory for the Neuroi, as humanity had not yet figured out a means to effectively fight against them and was forced to constantly retreat. Despite losing the First Neuroi War, humanity still prevails in places where Neuroi attacks are rare.
It was eventually discovered that witches could block the Neuroi's miasma and beam attacks, allowing them to get close enough to Neuroi to potentially fight back. To complement witches in battle, the Striker Unit was developed by Dr. Miyafuji in 1935. Older units were believed to already be in use after the First Neuroi War. It used a magic engine to enhance a witch's magical abilities, allowing them to fly and to carry weaponry that can otherwise only be mounted on vehicles. The new breed of witches, who flew with these new Striker Units, became known as Strike Witches.
The first uses of Strike Witches in battle were in Hispania in 1936 and during the Fuso Sea Incident of 1937, in which an exploratory group of Neuroi approached Fuso. The inhabitants of Fuso were prepared for this battle, as they'd been awakened to the renewed threat of the Neuroi after sightings in Hispania, and they had been training witches in anticipation of sending them to Hispania. The battle was a large victory for the witches, and it helped bring such aces as Sakamoto Mio and Anabuki Tomoko to fame. Possibly as a result of their resounding defeat here, the Neuroi have not attacked Fuso since this incident.
In 1939, the Neuroi launched an attack of unprecedented scale on mainland Europe. As the nations there had gotten used to peace, they were unprepared for the assault and began to fall one after another. Ostmark was hit first and fell quickly. Karlsland was able to hold out against the Neuroi for much longer, but they were still eventually forced to retreat, with their military scattered to the east and west. Gallia wasn't able to hold out much longer against a ground assault from the Neuroi, and the military forces there focused their efforts on evacuating as many people as possible to Britannia , which, as an island nation, was much more defensible against the Neuroi.
At the same time, the Neuroi expanded into the east, conquering much of Orussia and expanding until the Suomus Misfits Squad was able to score some surprising victories and hold the line against the advancing Neuroi. The victories of this squadron inspired the formation of Joint Fighter Wings, which were comprised of witches from various nations working together, where they were able to bring varied technologies and skill sets together.
The Neuroi expanded southwards into Africa as well, although humanity found it much easier to defend the massive plains of this continent. The incredible visibility meant that the plains of Africa were the one and only place where conventional artillery could out-range Neuroi weaponry, allowing Africa to be defended by a much smaller complement of witches than other fronts of the battle.
Eventually, the efforts of the witches, in particular the 501st Joint Fighter Wing, allowed humanity to regain territory it had lost to the Neuroi. The 501st was responsible for the destruction of the Neuroi hives over both Gallia and Romagna. Both of these hives were destroyed in part due to efforts to mimic Neuroi technology. In Gallia, the Warlock was designed using research performed on a recovered Neuroi core, but it was deployed before testing was completed and turned on humanity after attempting to control the Neuroi. When the Warlock's core was destroyed, its connection to the Neuroi in Gallia resulted in a chain reaction that destroyed all Neuroi in the airspace and liberated Gallia.
Similarly, the hive over Romagna was attacked by the battleship Yamato after it had been "Neuroified." Although the Yamato was successfully able to destroy the hive, the aftermath saw the formation of a massive Neuroi core which was attached to the Yamato and Sakamoto Mio, using the latter's shields to protect itself from all attacks. The core was only able to be destroyed when Miyafuji Yoshika used up all of the magical ability within her body to perform the legendary Shin Reppuzan attack on the core. With the destruction of this core, all remaining Neuroi in Romagnan and Venezian airspace were destroyed.
As of 1945, Neuroi hives have been confirmed in the following regions.
- Berlin's airspace - this massive hive is the final target of the European Resistance Operation; this hive is noted as being one of the most heavily defended Neuroi Hives in existence with massive, towering and powerful Neuroi defensive siege tower units surrounding the ruined city of Berlin and containing a massive garrison hoard of Neuroi units. - Presented in Strike Witches Road to Berlin.
- "Wolf" - the lead hive in charge of defending Berlins airspace. While it is stationed and tasked with the defense of Berlin itself, it also was stationed 4 Kilometers to the Southeast of Kiel where it deployed Neuroi rockets to make deep penetrating rocket strikes on Keil's strategically important port in order to delay the assault by the allies on Berlin. - Presented in Road to Berlin. Opposed the 501st. Destroyed thanks to the efforts of the 501st and supporting allied forces.
- Black Sea's coast - the very first hive that appeared at the beginning of the Second Neuroi War.
- Elbe River - located in the vicinity of the river's mouth, it is currently being opposed by the 506th Joint Fighter Wing.
- East Gallia - destroyed thanks to the efforts of the 501st Joint Fighter Wing.
- Nuremberg - presented in the movie.
- Ostmark's airspace - apparently multiple hives can be found in this region. Portions of the easternmost areas of Karlsland and the westernmost areas of Orussia are also in their sphere of influence.
- Prague - presented in the movie.
- South Karlsland - apparently located near the Rhine river, destroyed by a stronger hive that later established itself in Venezia.
- South Novgorov / "Vsiliy" - presented in Episode 3 of Brave Witches. Currently being opposed by the 502nd Joint Fighter Wing.
- Sphinx's airspace - currently being opposed by the 31st Joint Fighter Squadron Africa.
- Venezia - destroyed thanks to the efforts of the 501st Joint Fighter Wing.
- "Grigori" - presented in Episode 3 of Brave Witches. located at the White Sea. Destroyed by the 502nd Joint Fighter Wing.
- "Anna" - also presented in Episode 3 of Brave Witches. located somewhere in Western Orussia, Currently being opposed by the 502nd Joint Fighter Wing.
- "Vzsily"- another hive presented in Brave Witches located in Western Orussia a few miles away from the "Anna" hive; located to be in close proximity to Homyel and Kiev. Opposed by the 502nd Joint Fighter Wing.
Physical Traits, Biology and Technology
The Average Neuroi is a supernatural alien being with a black armored shell. Most Neuroi of old were monsters, beasts and mythological creatures but by the 17th century and the First Neuroi War they began to adapt and by the 1930s and 1940s the Neuroi reached the point where "creature" and "machine" has become one and the same. Neuroi can have an all black, smooth looking body with red marking ports, while others may have a black body with hexagon pattern and red hexes for ports.
The surface shell structure of an average, conventional tank unit Neuroi or large aircraft type Neuroi, is postulated to be much like the surface structure of a tank, such Neuroi units have armor that spread out evenly and completely in a three dimensional shape. The Neuroi armor structure consists of a basalt, crystalline substance with some metal elements and composition consisting of a solid shape and patterned with honeycomb structure as a hexagonal body, forming a shell like pattern akin to a beehive or a turtle's shell. The consistency of the armored shell of the aforementioned large and capital air unit Neuroi and heavy ground type Neuroi is said to be a close equivalent in durability to the spherical composite armor known as "Chobham armor" that is used in tanks. Given observable evidence this exact composition may vary from specific Neuroi unit types and sizes to be even stronger and more durable than average or alternatively to being somewhat weaker than average. To add in Neuroi's abilities of regeneration makes Neuroi defensive abilities rather formidable, and depending on how fast any given Neuroi can regenerate damage could make a given Neuroi even more formidable.
In the armored body of the shell of non-drone Neuroi is located a core, the core is a red Icosahedron shaped as a Dodecahedron and is embedded inside the Neuroi protective, armored shell. With this core, a Neuroi is autonomous and performs automatic repair. When this core is destroyed, the Neuroi "collapses" and typically becomes a particle of light and disappears into a mass of white, glowing shards, although some Neuroi falling apart as large chunks or merely remaining as a relatively intact but 'dead' shell have been occasionally noted but are rather uncommon on average. The core is typically often hidden in a place not visible to the naked eye; whether inside the body of the Neuroi itself or inside a secondary, main body. The magical "demon eye" of Sakamoto and similar witches' magic eyes have the power to discover the position of the Neuroi's core; although the exact extent, means and effective accuracy to pinpoint the core varies from witch to witch. Cores can come in several sizes and can even possess unique traits to increase survivability depending on the Neuroi unit type: some Neuroi can move their cores around inside its protective shell, others have what's known as "a core within a core" to not only move around inside of but also obscure the true core and confuse attempts at detecting and pinpointing the Neuroi true core. Some Neuroi can hide their cores inside separate units with a larger body to distract enemy attack and a smaller body used to avoid detection. Other Neuroi still can break up their bodies to mix up an enemy in trying to find the core and swarm in a disorienting fashion for swarming attacks. Meanwhile, other Neuroi have been documented to possess optical stealth abilities or shape changing. A rare number of Neuroi can even have cores that are large and extremely dense and durable and thus are difficult to shatter, and rarer still some Neuroi cores can even survive an initial shattering attempt of their cores and actually regenerate their cores as well as their bodies to a point; but few Neuroi are capable or powerful enough to do this latter example, or sustain it more than once or maybe twice.
In the past Neuroi seemed to rely on their physical girth and monstrous, beast like claws, talons, teeth or other appendages as weapons, as well as Miasma gas. The possibility of any other means of attack of a more supernatural nature, while certainly plausible, it's difficult to say how prevalent and to what the exact extent of such abilities would have entailed between given Neuroi of such classical eras.
However, shortly after the 17th century Neuroi began to develop more conventional and machine-like weapons. The first Neuroi projectiles were hedgehog like spikes and spines, soon followed by Neuroi made physical bullets that have been in widespread use in the 1930s and even into the mid 1940s, with the Fuso sea incident seeing Neuroi bullets becoming stronger and denser than before, making it initially difficult for witches with the technical limitations and tactics of the time to defend against Neuroi bullet and attacks. However, during the Fuso Sea Incident the first recording of Neuroi beam weapons and faster shell regeneration was made, with Neuroi beam weapons becoming much more stronger and displays of their shocking, awe inspiring power and destruction being made clear and apparent.
With time however, the military in general, and witches in particular, begin to adapt to the new machinations and power increase of the Neuroi and their advancements in power and technology.
After 1943 however not only has the enhanced regenerative capability continue to be in play as long as the core is not destroyed: the new Neuroi have been enhanced with regenerative abilities faster than the reloading time of the main gun of a battleship like the Yamato, and in the case of Neuroi similar to the one the 501st fought to defend the Yamato: the destruction point also appeared to recover and regenerate. It has been noted for this Neuroi behavior that to regenerate the surface, the inside may become hollow immediately after starting the playback.
The new path of evolution the Neuroi of the past was almost the one imitating the weapon and machines that the human race have made. However the new Neuroi are looking for the appearance other than that of the human race's weapons.
The Neuroi show great variety in their designs, and their models have evolved as the war has progressed. Their designs have typically progressed from small models that are employed en masse to fewer, larger models.
With the exception of drones, all models of Neuroi in use by 1944 have a single, critical weak-point: their core, a red polyhedron whose size varies with the size of the Neuroi. If the core is destroyed, the entire Neuroi will be destroyed, along with any drones it has deployed and any other Neuroi under its control. The core is typically buried within the center of the Neuroi, although exceptions exist (such as one Neuroi which kept its core in a distant bug-like Neuroi). Neuroi surround their core with black armor that shows a hexagonal pattern. Certain patches of this armor are colored red, which signifies the location of the Neuroi's energy weapons.
Earlier models of Neuroi were vastly different in design, and more closely resembled conventional aircraft. They lacked the cores and regenerative abilities seen in later models, and could be shot down by damaging their engines or dealing enough damage to their wings. It is unknown at what point the Neuroi developed their modern designs.
The Neuroi from the Movie seems to have the ability to block radio communication, teleport and avoid detection by Heidemarie W. Schnaufer's antennae (until it comes within close range) for unknown reasons. The model of Neuroi that prominently appeared in the Movie possessed an alternate form, the purpose of which is also unknown.
Also revealed in the movie is that before the advent of the 17th century ancient Neuroi often took more animal-like, monstrous or "demonic" in form, judging from ancient paintings, drawings and scripts that show Neuroi-like creatures locked in battle with witches and humanity, indicating that the Neuroi are an old enemy of humanity and witch-kind, and only recently Neuroi have grown and adapted to take on more powerful vehicle-like forms.
While beast type and Machine-beast type Neuroi have been noted and seen in battles even up into 1945; they aren't quite common to the same degree as more vehicle like Neuroi.
Neuroi are shown to have not only varied forms and iterations of such forms, but also various abilities apart from regeneration and beam attacks; aside from some Neuroi being able to transform, deploy drones, assimilate human technology to make into other Neuroi, and deploy deadly Miasma, there are Neuroi that have been seen and documented to posses abilities that permit them to deploy Chaff to disrupt and jam radio transmissions as well as both conventional and magical radar, being able to absorb electrical energy to increase their power and sabotage power sources, an instance of Neuroi being able to make, control and weaponize its own personal adverse weather conditions like Blizzards to hide movement of itself and Neuroi allied units, change the battlefield and even weaponize the weather for attack and defense, a case where a Neuroi artillery spotter type unit could roughly change it's shape and appearance (if at times crudely) to hide itself while deploying an Electromagnetic signal to mark targets for Neuroi Artillery units to fire upon, and finally, with the case of the Spinx, being able to ask it's opponents a question that, if unable to be answered, keeps the recipients of the question frozen in place and vulnerable to being attacked. It's likely that certain kinds of Neuroi may posses even more of their own unique and specialized abilities outside of the conventionally expected Neuroi abilities; allowing for greater power, abilities, movement and tactical options.
A small Neuroi deployed in the defense of a larger Neuroi. Drones do not have cores of their own and cannot regenerate themselves. It is unknown whether destroyed drones can be regenerated by their parent Neuroi, but this has not been seen in combat.
The standard flying class of Neuroi, and the most common type of Neuroi seen in the anime. A large-type Neuroi is comparable in size to a large aircraft at its smallest, but they can also be much larger. A single large-type Neuroi is capable of overpowering fleets of ships or multiple wings of conventional fighters. When possible, a wing of six or more witches is used to take down a large-type, although it is possible for a single witch to take down a large-type with sufficient skill or luck. Certain large-types are capable of deploying drones, typically by splitting their bodies into multiple parts.
Unofficial name for unique models of Neuroi which are deployed for specific purposes. There is no apparent upper limit to the possible size of Neuroi, with one even manifesting as a 30 km-high tower. They still suffer the weakness of having a single core, which will result in the destruction of the entire Neuroi when destroyed, though it is usually much better defended. Capital Neuroi are almost always able to deploy numerous drones in their defense.
The ground-based counterpart to large-type Neuroi. Heavies typically resemble tanks, and although they are much more powerful than human tanks, it is possible to defeat them with conventional anti-tank measures, or potentially with artillery, offshore battleship bombardment and minefields. Certain heavies take a four-legged form, nicknamed "turtles." Tank Witches are the preferred countermeasure, followed by Strike Witches, as heavies are usually able to overwhelm most conventional forces once they are in range to use their weapons. In flat terrain where artillery can accurately shoot outside of their visible range, it is often possible for them to destroy heavies before the heavies are in range to counterattack.
Extremely large ground-based Neuroi that are exceedingly difficult to destroy. They are virtually impossible to destroy with conventional weaponry, and even witches face many difficulties in destroying them, often owing to size, firepower and both thickness the durability of the Neuroi's metal shell. One example of an Ultra-heavy Neuroi was a massive Neuroi that consisted of an assimilated ship's hull. Such Neuroi combat platforms are heavily armed and armored and it's implied that even their cores are more durable compared to other Neuroi and tremendous amounts of firepower are required to breach the armored shell and a bit more firepower than normal to destroy the core.
Some Neuroi have taken forms resembling Strike Witches, in some cases even being modeled after individual witches. In these cases, the Neuroi are almost exactly as powerful as the witches they mimic. However, they lack the experience of witches and their capability for teamwork, so these Neuroi are no match for an experienced wing of witches. The Neuroi witches learned through espionage, after a brainwashed witch was released to train with other witches, while transmitting tactics back to the Neuroi. The Neuroi witches were also assisted by brainwashed witches in battle.
A witch-like Neuroi, known as X-11 (aka Neuroi Girl) was seen again much later in the war, over the Brittanian Channel and later in Venezia. This Neuroi was not designed to mimic any individual witch, and it used standard Neuroi weaponry and defenses rather than carrying guns like the previous Neuroi witches. In the first encounter with this Neuroi, Miyafuji Yoshika attempted to make contact with it, and she gained knowledge of the Warlock project as a result. However, the Neuroi witch was destroyed by the Warlock before its plans could be ascertained. Another witch-like Neuroi was seen over Venezia, where Takei Junko attempted to communicate with it. This attempt was interrupted by the appearance of the Super Hive and the destruction of the Neuroi witch by other Neuroi. The witch type Neuroi's abilities and combat tactics were unique and atypical of most Neuroi: as the X-11 class didn't seem to engage in hostilities unless fired upon and seemed to attempt communication with witches that made contact with it. When provoked into fighting the X-11 Neuroi's attacks included firing a large, wild swath of multi-beams from the "wings" on its striker and firing a large, singular, powerful beam from its "hands". It was also noted to have some kind of defensive countermeasure consisting of what appears to be a smokescreen barrier that seems to obscure the X-11 from attack and possibly deflect, or at least reflect, bullets. The X-11 also displayed apparent short range teleportation abilities.
Small and Medium-types
Smaller aerial Neuroi, typically deployed en masse to defend hives. Although rarely seen in the anime, as the Neuroi have shifted to primarily using large-types for offense, small and medium-types are the greatest contributors to witches' kill counts. As they lack the armor of large-types, it is possible, though costly, for them to be destroyed by conventional weaponry. The Flying Goblet's frequently found in Africa fall under these categories (at least pertaining to small types).
While Neuroi commonly have been seen adopting the forms of various vehicles and aircraft: it's not uncommon or unheard of to see some form of Infantry Class Neuroi. Infantry class Neuroi fits in a very broad and complicated category. The vast majority of Neuroi infantry are, as to be expected; ground based infantry units, although the existence of "air based infantry", while of remote plausibility; is not very prolific or apparent, and it's difficult to parse out what would be qualifying as actual "air based infantry" or if it is actually a simple "small air unit". They appear to act, in a technical sense, a similar fashion as human infantry to attack and close with enemy infantry units and witches, although most of such tactics buy Neuroi infantry are rather simple, straightforward and rarely elegant. They have rudimentary abilities in terms of movement, attacks and general Neuroi attributes and seem to prefer to operate in groups, whether with other infantry or vehicle like Neuroi, sometimes even with both kinds of Neuroi at once. There is no uniform appearance however, various infantry Neuroi seen taking the forms ranging from cylinder like shapes on spider legs that can shoot small arm bullet projectiles or very weak beams. Some take the form of a large and ominous beast or insectoid like alien creature favoring the use of air attacks or heavier beam attacks. Others still even adopt a more humanoid looking infantry form, although they are strictly different and distinct from witch-class Neuroi, and in turn Witch-class Neuroi are not themselves classified as a "Neuroi infantry unit" due to the stark differences of power, ability's, strategic and tactical acumen and simple numbers, factors that witch-types are able to vastly outperform and overshadow your typical Neuroi infantry unit in, save for unit numbers which for X-11 witch types are very small by comparison. That being said, Infantry class could still pose a problem in thanks to the use of large numbers to swarm human squads, and in such cases it isn't unheard of for witches to fight Neuroi infantry units while surrounded on all sides by an infantry hoard. Another detail of note is that there are at times some apparent form of chain of command in Neuroi ranks is observed, what with Neuroi infantry noted as being led, at times, by a "leader" unit that is able to help keep its underlings morale and give more effective direction and more cunning tactical and strategic troop movement. Such a leader infantry unit may also be a bit more competent than it's peers as an infantry class, but it could still be vulnerable from attacks. It's noted that the destruction of Neuroi leader units, in particular Infantry class Leader units: often results in other units under its command to either fall into disarray to be easily finished off, or breaking into outright retreat from the battlefield, or even cases where other units that were somehow linked to their leader being spontaneously destroyed alongside the leader Neuroi following it's near immediate destruction. Another note of interest is that there are at times noted to be Neuroi would be said to fill the role of a "Heavy Infantry" role, a large, infantry type Neuroi with greater strength and destructive power from most standard small or medium-sized Neuroi infantry that, depending on exact infantry unit style, can punch out tanks and send them flying or otherwise use more powerful attacks, whether physically in melee or use of bullets or beam attacks; although such Neuroi heavy infantry appear to be few in number and seemingly not very widespread. That being said, it's reasonable to infer that they are harder to take down than normal Neuroi infantry of small or medium size.
The primary Neuroi base of operations, which generates lesser Neuroi to fight in its offense and defense. Hives can appear seemingly out of nowhere, and there is no known way to predict where they will appear. From the outside, hives appear as a roughly conical black funnel cloud. This cloud like cone is in fact the Neuroi's deadly Miasma, providing both hive protection and territory control functions as well as possibly having a rejuvenating or sustaining effect on Neuroi to permit them to operate effectively over a period of time; possibly acting as a rejuvenating means of sustenance though this is still uncertain. The hives' inner walls carry the characteristic black hexagon pattern. When a hive is destroyed, all Neuroi that it has spawned are typically also destroyed and the Misama cloud dissipates. The dimensions of a standard Neuroi Hive's core size is 20 km.<5" tall. The standard maximum altitude of a Neuroi hive is 4000m (surface of the earth to the bottom of the hive). And lastly, the standard total height of a Neuroi hive itself is also 20 km in diameter and 4000m (4 km) tall.
A unique hive that appeared in Romagnan and Venezian airspace in 1945. The Super-Hive was an order of magnitude larger than normal hives, and was colored dark green rather than pitch black. It also possessed a large spherical, armored area below the bottom of the cloud-like portion of the Miasma gas cloud surrounding the hive, which is not present in normal hives. While the core of a normal hive is a little larger than the core of a large-type Neuroi, the Super-Hive's core was far larger, comparable in size to a normal hive. The core also showed the ability to learn very quickly, being able to generate shields after partially absorbing Sakamoto Mio. A super hive measures 300 km in diameter and its height is large enough to fly through the stratosphere (50 km high).
A nest can be best described a ground bound "hive" that nominally deploys ground based Neuroi units, although some small and medium class air units can and have been documented to deploy from Nests as well in supporting roles. Used as a type of Neuroi ground base, they are seen as structures, caverns and tunnels leading into the ground, although the exact size and shape can vary. It can be ventured that the interiors are similar to that of hives. The Anonymous Metropolis (AKA: "The Pyramid with no name") that was stumbled upon in Africa during the Battle of the Sphinx was one such example that is well known; this particular nest appeared when a centuries-old sealing spell that was made to seal away the Anonymous Metropolis was broken by its mere existence becoming known, which released the nest as well as all the Neuroi that were sealed away with it. It's not certain how many nests there are in the Neuroi war outside of the example found during the battle of the Sphinx. While there doesn't appear to be a sort of miasma cloud on the surface of a nest's immediate territory; it's uncertain if, but possible, underground tunnels and chambers may contain Miasma gas or alternatively individual Neuroi units who may produce miasma gas; however such postulations are currently conjecture.
On two occasions, allied forces have used Neuroi technology to enhance their own weaponry. The first instance of this was the Warlock, which used a captured Neuroi core as its energy source. After it was deployed, the Warlock began to show independence from its controllers. It eventually coated itself in Neuroi armor, took control of all Neuroi in Gallian airspace, and turned on the allied forces. When its core was destroyed, the Warlock was destroyed along with the Gallian hive and all other nearby Neuroi.
The second instance of the allied forces using Neuroi technology was with the Neuroification of the Yamato. Unlike the Warlock, the Yamato remained firmly under Allied control. It gained Neuroi armor, beam weaponry, regeneration, and the ability to fly. After destroying the shell of the Super-Hive, the Yamato was partially trapped within the hive's core until the core's destruction.
Behavior, Abilities and Tactics
As already noted: Neuroi possess a durable armor shell that is of unknown metallic-crystalline compound that is able to boast a considerable degree of resilience to attacks and damage. A Neuroi's armor durability typically varies in resilience between individual Neuroi class types but even with that in mind it's noted that a number of small Neuroi can withstand a short burst of gunfire from conventional units before being destroyed, though others seem to possess a lower resilience; others still like the Laro's-Kai are heavily resilient for being small sized. Typically larger Neuroi tend to be more well armored with massive Neuroi possessing very strong, dense armor that the majority of conventional heavy weapon systems can't breach and sometimes not even magically augmented heavy weapon type small arms used by a witch can inflict any damage depending on the weapon used and the type of Neuroi being fought. In the case of a Laro's-Kai even the Type 99-2 Model 2 Kai autocannon used by Anabuki Tomoko was noted to have some difficulty in breaching the armored hide of this specific class of Neuroi compared to its baseline counterpart even after a sustained burst of automatic fire that would have shot down the baseline Laros, forcing Tomoko into close combat with her sword for the kill; presumably because Tomoko's magical power can focus itself into the sharpened Fuso blade, allowing a great amount of magic to be imbued and focused into the swords slashing blade.
Aside from a Neuroi's armored shell: Neuroi posses a very powerful, and terrifying ability to regenerate any damage sustained to their armored shells and bodies. All non-drone type Neuroi that posses a core can regenerate to some varied degrees and can even regenerate limbs, wings and other body parts that have been shot off or blown up. Some Neuroi have faster regenerative abilities than other's of their kind. The destruction of a Neuroi's core destroys the Neuroi and as a consequence, prevents regeneration of damage. The importance of a Neuroi's core as an exploitable weak-point isn't lost on both humanity and the Neuroi themselves respectively. However, because of this, there have been attempts by the Neuroi to ensure the protection of their vital cores outside of merely encasing their core in a hard metallic shell and using powerful weapons and regeneration: a recent discovery made is that some uncommon Neuroi units of capital class or greater size posses a "Core within a Core": with the outer core acting as a protective shield for the real or "true" core; the actual core typically is shielded, cloaked and moves around inside the outer core to prevent the destruction of its core. Attacks to this type of core are initially thought to successfully destroy the core only for shocked witch and conventional soldiers witnessing a seemingly destroyed Neuroi "resurrect" and regenerate after it's supposed destruction. Alternatively, some Neuroi units, while having a seemingly normal core; are able to move their core around inside their shells to confuse their attackers and prevent the destruction of their cores. In both cases: pinpoint detection and steadily aimed attacks are required to hit and destroy these cores when the nature of such cores are reviled; which is a very difficult feat to accomplish, and is enough of a challenge for even veteran witch squadrons.
The behavioral patterns of Neuroi tend to vary widely. These range from wild, uncontrolled, undisciplined, and unruly mobs to calculating, methodical, cautious, and regimented units. Neuroi behaviors and strategies tend to vary between platform types and classes; mostly at an independent, individual level but ever increasingly this is also becoming commonplace to see with well coordinated unit and combined arms squad level tactics and strategies in the Neuroi's ranks. It can and has been said that Neuroi are in a way like wolves in that there are purported "leaders" that lead and direct the subordinate members of the hoard. And once that leadership is removed: it's commonly typical that the subordinate followers will break into retreat home to Neuroi held territory. In any event, Neuroi are typically noted as being, in some way or another, hostile to humans, though rarely Neuroi have been documented as being hostile to other Neuroi. These cases are rare and it is not yet understood why a Neuroi would attack a fellow Neuroi. Some Neuroi, such as the X-11 class Witch type Neuroi, have also been noted as not showing overt aggression or any kind of initial belligerence towards humans unless fired upon and attacked first; though again, reasons for this abnormal behavior are unknown and only speculative.
The behavior of early Neuroi was likely akin more to beasts, monsters, and barbarian type units; acting either independently, small packs of creatures, or a loose horde of individuals fighting as a mob. It seems, however, that by the turn of the Magic power revolution and at the start of the First Neuroi War, this method of tactics and combat doctrine has slowly started to change. From the events of the Battle of Hispania all the way to 1944 the Neuroi appear to be slowly changing tactics to being less predictable, having movement and attacks be very sudden, their inter-unit interaction facing development and growth, as well as becoming every increasingly better coordinated, seemingly adopting more contemporary military tactics. However, as noted in the 502nd interactions with a Neuroi artillery/spotter unit, the Neuroi appear to be grasping some basic form of understanding of human tactics, strategy, and warfare but appear to have difficulty in fully taking advantage of squad base unit tactics and trying to possibly overcome a learning curve of better implementing combat doctrine that appears to draw inspiration from modern human squad tactics; and doing so with some middling success. However, tactics that the Neuroi develop and deploy of their own ideology and paradigm, generally speaking, have proven to be very difficult for allied intelligence to fully and accurately track, at least consistently as far as Neuroi movement patterns are concerned, and their reliance on using large wave tactics and intimidating individual Neuroi classes with great offensive and defensive power has proven to be very effective for what it is.
Use of bizarre and strange Neuroi combat platforms with equally strange, unpredictable abilities also prove to work in providing outside-the-box problems that allied units and witch units can't easily and readily counter on the fly; requiring some time to figure out how to best counter such strange units and their abilities with unconventional tactics, ideas and approaches. Neuroi that specialize in high speed and reaching operational high altitudes also prove challenging to face and destroy, and Neuroi that possess impressive stealth and evasion abilities are also very troublesome to detect by either radar or by sight and can prove a significant threat to allied units. While not fully capitalizing at times on such a fact, there have been times where Neuroi units have managed to, at least on a basic level, implement some limited form of squad based unit interaction and discipline and can even prove to be quite a competent, if not greater, threat; though for such cases it usually depends on the specific Neuroi units and what fellow kin platform they are working alongside.
Most small Neuroi, whether air or ground combat types, usually fulfill the roles of small air fighters, small sized infantry class, escorts to larger fighters and units, and large-scale swarm tactics in the sky or ground infantry, tanks (known as "armor" units), tank destroyers, artillery, anti-air, reconnaissance and other such units on the ground. Other units also typically fulfill various combat roles though specific abilities and tactics can vary with Neuroi being able to use bullets, bombs, rockets, artillery shells, or even beam weapons. There are also cases of Neuroi capable of using a combination of different weapon types.
Certain types and classes of Neuroi have also been noted as being able to transform to better improve their speed, attacks, abilities, and effectiveness or to initiate special abilities unique to the specific Neuroi class in question. In addition, there are Neuroi that can deploy core-less drones or even other individual Neuroi. Depending on the type of Neuroi, typically this is a feat capable by most huge type Neuroi and larger.
An interesting note is that Neuroi are at the moment documented to show disdain and aversion for large bodies of water, and generally seem to dislike water in general. Thus, there are no Neuroi units that are currently known to adopt class types that can travel upon or wage war upon the sea. While they can cross the skies above bodies of water, Neuroi appear to have very short flight times and appear to stay within a certain proximity to land in order to return to their lines and in turn return to the miasma. The exact reasons for this are vague, although some speculations put forth claim that Neuroi can't withstand or operate well in such excessively large quantities of water, possibly disrupting their biology as well as having little to no access to resources of the land for their own purposes. The only times Neuroi have spent an extended time over seas and oceans are to conduct close to shore patrols and combat missions or infiltration, or as a sort of one way trip invasion that demands a lot of time, resources and Neuroi unit support of kin units; as seen during the Fuso Sea incident. Neuroi Miasma is alleged to be Corrosive, and while the exact nature and composition of the Neuroi's Miasma is not yet fully outlined, it's known to be extremely harmful to humans, with children especially being highly susceptible to harm from Miasma exposure: only witches can be exposed to Miasma and not be harmed by such deadly clouds of corrosive gas thanks to their magic protecting them. While the Neuroi's full and exact use of Miasma is not completely outlined, some implications indicate that Miasma, aside from being used to control and hold territory the Neuroi occupy, Miasma may also serve some kind of sustaining property for Neuroi, as it's noted that Neuroi can't operate too far or too long outside of Miasma for some indeterminate amount of time; as they must return to the Miasma once this time is up: possibly to replenish strength and energy or possibly for some other, or at least additive reason. It's unknown if all Neuroi can deploy and control miasma, but there are certain Neuroi classes that are noted to deploy and make liberal use of Miasma even in battle and during invasions.
In addition, while Neuroi can and have crossed forests and frozen lakes to accomplish objectives; it's apparent that such terrain is still rather disliked by Neuroi due to the nature of the layout of such terrain, risk of ambush, the difficulty traversing the claustrophobic tree line, and risk of the ice breaking and drowning in the frigid waters. In such cases, travel is likely done only if absolutely necessary and if other, specifically designed Neuroi units can ensure clear and secure paths across the forests or frozen lakes. Neuroi land units do seem to prefer traveling and moving through lowland areas. Open fields and other open terrains, while providing full freedom of movement and permitting easy, unrestrained use of large wave tactics or easy deployment and implementation of ultraheavy type Neuroi, there is little means of protection or defensive cover for Neuroi unless massive supporting units provide support for smaller Neuroi units, using massive hoards to overwhelm human units or using such units as diversions for specialized Neuroi units.
- A Neuroi Core's rotation speed is at about 30 RPM
- Information gleaned from the Strike Witches Official Fanbooks note that though early history: Neuroi were simply referred to as "It", and mentions that they're an abnormal existence that has attacked humanity throughout the ages. This further affirms more recent evidence of art though the ages showing ancient Neuroi monsters locked in combat against humanity and it's witches.
- Before 1914, the Neuroi apparently had no formal name outside of Fuso. They were just simply called "It". This does however, raise question of how and when they were also named Rätsel, which in 1241: The Mongol Empire, together with the Germania Knights,fought Neuroi of old (referred to directly as Rätsel) in Wahlstatt.
- In Fuso's ancient times and the Middle Ages, Neuroi were originally called "Kaii" (mystery/strangeness) due to their appearance causing a single localized disaster, for which they became known as "Kaii" by Fuso since until much recently in history.
- Mention in the Official Fanbook was made in regards to Miasma, which was stated as being normally deadly to any living being. However, it was found that Witches were able to resist the effects of Miasma. It was thanks to the witches resistance and ultimate immunity towards Miasma that caused witches to become the first responders to each Neuroi-inflicted disaster, since they could brave Neuroi and their Miasma without the same mortal peril other people and living things would face.
- Humanity has produced numerous artwork of the classical and medieval ages time period of the witches fighting Neuroi of old. Opening scenes of the Strike Witches Movie shows a few examples of such art.
- The Official Strike Witches fanbook (Season 1) notes that, apparently before 1914, the Neuroi had always appeared singularly, in isolation from each other. In 1914 though, the Neuroi appeared for the first time in large numbers, and even cooperating with each other. The Neuroi invaded northern Orussia and Ostmark, thus triggering the war called "The Great War" (although the fanbook also seems to call this war a "First World War", though it likely is referred to in setting as "The First Neuroi War" come the events of the 2nd Neuroi War). Given that there are historical examples of old Neuroi infesting large regions in mass, if in a rare, occasional fashion; this information seems to indicate that 1914 is likely the first time the Neuroi have amassed themselves in their greatest numbers yet in history for the first time, and with a degree of co-operation with their kin never seen before.
- Strangely; the official season one fanbook mentions that when the world governments finally "destroyed" the Neuroi (if at it seems great cost), they chose to keep much of the details of the Great War and the Neuroi classified, such that the public apparently by now is almost completely unaware of the details of the Great War other than the fact that it had happened.
- While the Neuroi during the Great War were "destroyed"; it was likely that a considerable number of surviving Neuroi remained to have a lower level presence in the interwar years on the periphery. It's possible that these remaining Neuroi forces continued to raid and harass the European nations while they were building their forces and strength in preparation for the Fuso Sea Incident and 2nd Neuroi War.
- The Strike Witches Season One Official fanbook notes that in 1939, the Neuroi began a full invasion of humanity. The Neuroi established a nest in Europe, and began the creation and deployment of new Neuroi that are described as a fusion of machines and living beings. Two implications from this is that smaller scale proxy wars between humanity and Neuroi occurred in the inter war years against smaller level Neuroi incursions, and that by this point; the Neuroi have finally fully adopted a form that combined machine with creature; implying that Neuroi were originally more creature like than machine-like until recent historical periods. By now; Neuroi nomminally take the shape of fighters, bombers, tanks, and ships to destroy humanity.
- The Neuroi's beam attacks are explicitly described as an "optical heat ray attack" in the Official Season One Fanbook. These "heat ray attacks" are emitted from the surface layer of a Neuroi's shell.
- The paragraph describing Neuroi beam attacks goes on to talk about how the destructive power of the beam can be and is enormous; quoted as "cutting into and destroying everything like a sharp blade."
- The Neuroi's Beam Port, referred to in the Official Fanbook as a "beam launcher", is fixed in whatever direction it's pointing at. What's more, if the launcher is destroyed: it can't fire until it's been repaired.
- The official fanbook also describes the Neuroi's "skin"; the surface layer of a Neuroi has a honeycomb structure like turtle shells and basalt crystals. This distinct honeycomb structure is apparently made up of perfectly shaped polygons such as regular hexagons. The material is also layered 'like' composite armor, citing Chobham armor as an example. Though it seems that most Neuroi armor skin is merely "layered like Chobham armor" and not typically sharing the same toughness as Chobham armor, although some Neuroi with tougher, thicker armor may have comparable toughness to Chobham armor.
- While most Neuroi surface layers have a "honeycomb-like structure" for their skin; there are some notable Neuroi that lack this distinctive Honeycomb pattern.
- Incendiary shells have surprisingly good effect against Neuroi as a conventional countermeasure, since incendiary's disrupt a Neuroi regenerative powers, making it difficult for Neuroi to easily repair damage to their bodies.
- Neuroi beam attacks can be surprisingly effective against its own kin, as evidenced by the Warlock Unit's use of Neuroi beam technology against Neuroi unit's in battle and the superhive's destruction of the X-11 Witch-Type Neuroi the 504th attempted to parlay with.
- A Neuroi's Core is a glowing, red dodecahedron embedded within the Neuroi's body. It appears Neuroi with a core are able to act autonomously and repair itself. When the core is destroyed, the Neuroi collapses and disappears into particles of light, which are known in canon as "Fragments/Neuroi Fragments",
- The core of a Neuroi is usually hidden in places hidden from the naked eye, save for those exceptions where the Neuroi has them on the outside.
- Sakamoto's Magic Eye (and likely all other witches with this ability) has the ability to locate the core's position within the Neuroi's body.
- The fandom sometimes refers to a destroyed Neuroi's Fragments as "Shards", due to the glowing pieces as being like shining shards of glass.