Machina Biology
Despite how extremely advanced the sciences at play in a Machina's body are, they do not possess many separate organ systems. In basic terms, a Machina's body consists of her Core in the center of her chest to provide power from matter reactions, her brain and her horns for thinking and networking, her various power conduits such as her spine, her breasts to create M2 Nanomachines, and her sex organs. These are the universal systems found in all Machina; both anatomically simple yet so scientifically advanced it is almost fantastical.
Machinium
Whilst humans are based on carbon and other elements to form their bodies, Machina are made of Machinium. Machinium is a combination of biometals unique to M2-based life and embedded M2 Nanomachines. Biometals are a group of ultra-dense polymer superalloys which vary in their chemical compositions, but universally feature extreme strength and density. In fact the density of Machinium is approximately 35,000kg/m3 for regular Machina and other M2-Based Life-Forms, and approximately 50,000kg/m3 for Queens. The reason for the variation in composition is because Machinium always has M2 Nanomachines embedded in it which alter the chemical composition of the biometals in order to adapt the Machinium tissue to new needs, particularly stresses. As an example, if a Machina is hit with a heat-based weapon, the M2 Nanomachines in her body will learn as they repair her, and alter her outer casing's chemical composition to become more heat-resistant. Embedded M2 Nanomachines also carry out repairs and growth, so Machinium appears to be a living metal when observed.
A Machina's body is almost entirely comprised of Machinium. A Machina's face and other soft parts of her 'skin' casing are a softer form of Machinium that feels like plush rubber, yet hardens in response to impacts. Elsewhere on the Machina's body there may be semi-hard armour that is again a variant of Machinium which can flex somewhat but has a higher ability to harden in response to impacts. Actual armour plate is Machinium too, much more capable of withstanding damage, yet its ability to feel things is much more dull than elsewhere. Internally, a Machina's bones are made of hardened Machinium, while her soft tissues and cell-structures are made of softer Machinium. This means a Machina's body is extremely dense and possesses a very large mass for their size, which is handled by the Anti-Inertia Systems outlined below.
In order for Machinium to adapt to new stresses, grow, and heal, it must be supplied by a circulation system. Blood flows through all M2-Based Life-Forms for this reason. The blood is comprised of a synthetic fluid medium, raw materials, and free M2 Nanomachines. The circulating M2 Nanomachines supply power from their bodies to the embedded M2 Nanomachines, as well as carrying materials with them to where they are needed. Without power supply to the embedded M2 Nanomachines, Machinium will break down over time, becoming inert liquid biometal alloy and deactivated M2 Nanomachines. For this reason, a sample of a Machina must be studied quickly before it begins disintegrating into simple monomers.
Core
In place of the heart and lungs of a human is a Machina's Core. The Core is responsible for supplying the Machina's body with useful materials and power. Anything the Machina eats, drinks, or breathes-in travels to the first part of the Core; the Matter-Shredders, located in the top spaces of her chest cavity. M2 Nanomachines and Machinium are immediately filtered out and enter the Machina's bloodstream. Next, matter is separated into free molecules. Useful molecules and atoms are again diverted into the bloodstream. Anything not deemed useful at the end of this process enters the Mass-Reactor in the center of the chest cavity. There, matter is converted almost 1:1 into energy to power the Machina's body. Leftover subatomic particles are taken to smaller organs attached to the Mass-Reactor where they can be fused together to make atoms and molecules the Machina needs but cannot find elsewhere. Due to the extremely complex mathematics involved in these reactions, a Larva is needed for the Core to operate at full output. This Core Larva monitors all the Core's processes and performs the unfathomable calculations necessary to maintain the reactions in the Core.
In the lower areas of the chest cavity attached to the Core assembly are the pumps for the Machina's circulatory system. The organs there pump the Machina's blood around her body and monitor the raw materials in the blood to ensure supply from the Core is sufficient. Incoming blood goes through the pumps, collects power and materials from the Core, then travels around the body before returning. Notably, the circulation systems do not feature a heartbeat. As the pump organs develop around the human heart, the heart will stop beating, which can be significant moment in a Machina's early development.
Due to how the Core only requires matter for fuel, any matter will do for survival. However, Machina retain the ability to fully appreciate human food with far greater sensory definition. In addition, because most metals are nutritious for Machina, their bodies also interpret these metals to be tasty. As a result, both human food and most metals have appreciable tastes for a Machina.
Power Systems
The energy produced by the Machina's Core is supplied to all her cells by her power circuitry, which are superconducting circuits that supply her entire body with power. These begin as large conduits exiting the Core area, such as the Machina's spine or the various pipes that are somewhat embedded into her body's exterior, before branching off and becoming progressively smaller, similar to blood vessels. The circuitry of a Machina supplies constant power to all her cells and tissues, and is complimented by the ability of the M2 Nanomachines in her blood, who are able to supply bursts of power to areas where it is needed. These power circuits usually run alongside the paths of blood vessels, and similarly they almost always have nerve circuits running alongside them.
An interesting note; the presence of an extra eye on a Machina's body does not always denote a bonded Larva. Eyes can form on a Machina's body wherever power is concentrated by their systems. This is the reason almost all Machina seem to have eyes located on their penises, despite not bonding a Larva to it. It is also the reason for the third eye possessed by all Queen-class Machina.
Anti_Inertia System
A Machina is extremely dense. A normal Category 3 Machina has a density of approximately 35,000kg/m3, while a Queen has a density of approximately 50,000kg/m3, due to being made of Machinium. A Category 3 Machina standing the usual height of 200 cm and with average equipment will generally have a weight of 500 kilograms, but a mass of 5 metric tonnes. The Category 3 Machina's equipment constitutes half of the weight and mass. A Queen with a Fusion-type Throne of the same height will generally have a weight of 1.5 metric tonnes, but a mass of 15 metric tonnes. The Queen's Throne constitutes two-thirds of the weight and mass in this instance, but Thrones can vary greatly.
This is because of the Anti-Inertia Systems that all Machina possess. A Machina's spine transmits massive amounts of power along its length. It has been adapted to create a field with some of this power that reduces the inertia of the Machina and causes her to weigh approximately 10x less than her mass. This way, the Machina is neither crushed under her own weight nor does she casually crush her environment with her basic movements. As the field is tied to the power being transmitted along the length of her spine, these systems cannot be deactivated by the Machina even if she wanted to.
Gyno Mode
Gyno Mode is an ability possessed by Queens and some Category 3 Machina who have been Blessed by their Queens. It is a state of maximum possible performance where power is rerouted from all non-essential systems to the Machina's essential combat systems, such as her M2 production, her motors and muscles, and her Machinium armour and skin casings. In addition, the essential systems have their power consumption limitations lifted. What this means is that the Machina is operating at her fastest, strongest, and most durable, but is outpacing her power production. Therefore, a Machina cannot maintain Gyno Mode indefinitely and must have a stockpile of power available to initiate it. Blessed Category 3 Machina can only maintain Gyno Mode for a number of minutes, whilst Queens can maintain Gyno Mode for one or more hours. The number of Larvae bonded to a Machina increases the duration of their Gyno Mode, since each of them is a miniature Core that can help offset the power consumption.
A Machina in Gyno Mode is easily spotted by the fact that her faceplate will have distorted into a more malign appearance, and that her normally-colourful and glowing skin has darkened to near-black, and very commonly their penises, testicles, and breasts expand. Many Machina may also visibly bulk up their muscles but this is not always the case.
Brain
A Machina's brain is an extremely complex biomechanical quantum computer. The biomechanical circuitry of the brain is continuously optimized and reshaped to increase efficiency and throughput. This is achieved thanks to the neuroplasticity inherited from the human brain it is based off. On its own, a Machina's brain is capable of incredible amounts of multitasking as well as massive amounts of calculations per second, exceeding humanity's best supercomputers by orders of magnitude. A large portion of a Machina's processing power is used to interpret her sensory data, as well as monitoring feedback from her systems in order to regulate their processes. Another portion of a Machina's processing power is devoted to supporting the Cluster she belongs to, where the Machina assists her sisters and her Queen with processing on various tasks as well as simply communicating her knowledge with them.
Machina do need to sleep on occasion to reset their processes and allow for optimization to occur. During this time, the M2 Nanomachines carry out physical changes as well as continuously looking for aspects of the Machina's mind to optimize. As her body carries out this mental optimization it can feel like a dream to the Machina, as deep memories appear in her mind and then leave as they are processed. These rest cycles have the added benefit of powering down the rest of the Machina's body so it too can be maintained by her M2 Nanomachines without the stresses of activity impeding them.
Horns
Linked directly to the Machina's brain are her horns, which are her link to other Machina. A Machina's horns house many cells that are specialized in communications. Each of these cells contains organelles that facilitate communications with a partner cell in another Machina's horns via quantum entanglement. Each entangled atom can transmit only one quantum bit at a time, so a Machina's horns grow based on the size of her Cluster and her own importance. The larger the Cluster is, the more connections the Machina must have, necessitating more quantum communication cells in a Machina's horns. The Machina's own importance also necessitates more of these cells so that she can transmit more data in a shorter amount of time by having parallel connections.
For Machina who are not Category 4, there is a finite range on these quantum communications due to the currently-unknown manner in which the Machina's communications cells 'hold' a quantum particle in its 'up' or 'down' state along with its partner at the other end of the connection. Category 2 Machina are the most limited of those who are connected to Clusters usually, due to their minimal power generation ability. Blessed Category 3 Machina perform better than their normal Category 3 comrades, and often act as a relay between their normal comrades and their Queen when a group is sent far away on a mission. Category 4 Queen-class Machina generate enough power to break through the mechanism limiting range in its entirety, allowing for limitless communication between them and the Main Cluster. However, because a lesser Machina must be in range to send or receive data, a Queen's range to her subordinates is functionally limited by the range of the subordinates.
Breasts
All Machina possess breasts which are the main location for the production of M2 Nanomachines. The now-biomechanical mammary glands are responsible for most of the synthesis of new M2 Nanomachines. Larger breasts generally indicate that a Machina is older, more advanced, and generally stronger, as the larger breasts have a greater production capacity. Production of M2 Nanomachines scales with the activity of the Machina's Core. When the Core raises its power output and supplies more raw materials to the bloodstream, the breasts increase their output automatically. Excess M2 Nanomachines are combined with surplus raw materials to create breastmilk. This breastmilk production will continue as long as there is excess M2 Nanomachines and materials for Machinium being supplied to the breasts, so a Machina in an excited state will leak breastmilk. The more powerful the Machina is, the more breastmilk she will leak.
Sex Organs
All Machina are futanari, possessing a complete set of female reproductive organs as well as a functional penis at least. A Machina's vagina leads to their womb, which is enlarged to take up most of their abdominal cavity. The womb is used to receive semen from other Machina, which is absorbed by the walls of the womb. Liquid Machinium and M2 Nanomachines that comprise the semen are allowed to enter the bloodstream and share Gene-Code improvements with the Machina's own M2 Nanomachines. The Machina's ovaries are very enlarged, and their purpose is to both create Larvae eggs which grow in the Machina's womb, and to create semen for her penis to ejaculate.
All Machina possess a penis, though there are two different styles of penis. Machina who lack external testicles are able to retract their penis into their bodies. The head of their penis will appear to be their clitoris until the penis is erected. Machina with testicles cannot retract their penis. For the most part it simply waves around in its erect state which can be maintained indefinitely, though if the Machina wants to, she can make it go semi-soft. Most Machina that were formerly human males will possess testicles by default, whilst any Machina who wants a set of testicles can easily gain them by bonding a Larva to the base of their penis.
Both a Machina's ovaries and testicles will create semen in response to the output levels of their Core. If the Core output raises, semen production will rise with it due to increased abundance of power and materials. An excited Machina will leak semen as a result of not being able to hold it all in, similar to her breastmilk.
Machina find it pleasurable when their Core output rises and their M2 fluids leak. This pleasure can cause further excitation, leading to a positive feedback loop. If a Machina decides she needs to cum for some reason, she can focus briefly on this excitation loop and will herself quickly to a strong orgasm, in effect letting them cum at will. Some Machina will go further than this and develop the ability to flex the correct muscles in sequence to shoot globs, or occasionally streams, of semen independently of their arousal status.
Fluids
Machina possess three main fluids: Blood, breastmilk, and semen.
Machina blood consists of a synthetic carrier fluid, M2 Nanomachines, and whatever molecules the M2 Nanomachine units are carrying. M2 Nanomachines fulfill the roles of red blood cells, white blood cells, and platelets simultaneously. When a Machina is injured, her blood clots the wounds very quickly and instantly begins rebuilding the damage. As mentioned above, not only do the M2 Nanomachines in the Machina's blood carry raw materials to cells, they also carry with them a charge of power that they can supply to an area of a Machina's body to provide adaptive power, complimenting the constant power of the main power circuitry.
Machina breastmilk is comprised of at least 50% liquid monomer biometals, with the rest being M2 Nanomachines. Its main purpose is to supply another Machina with Machinium components, which can be in short supply if a Machina is immature or damaged. It promotes growth and healing in the recipient Machina. It is thick and creamy in terms of texture, and like semen it is heavily laced with psychoactive chemicals that cause it to taste like the recipient's favourite flavours, whether the recipient is human or a Machina.
Machina semen is very rich in M2 Nanomachines; around 80% M2 by volume, with the rest being comprised of liquid monomer biometals. This density of M2 Nanomachines gives semen a thick, heavy, gooey texture. Machina semen has many purposes. When injected into a human body via sex, it provides a large amount of M2 Nanomachines to infect and corrupt the human, as well as a basic amount of biometal to make the Core quickly. When given to other Machina, it provides a large amount of genetic data, allowing for the recipient to quickly integrate the Gene-Code of the donor Machina. If a Machina injects her semen into a womb with a growing Larva in it, such as when Machina visit Breeder-class Machina, the Larva is nourished and its growth is accelerated.
Equipment
From their humanoid body, Machina almost always grow biomechanical equipment that helps them achieve their needs and goals. The capabilities of a Machina's equipment generally govern what 'Class' designation she is given. During Category 2 development, a Machina's M2 Nanomachines assess her personality, knowledge, and cultivated skills, and compare what they learn with their database of assimilated technology and knowledge in their Instinct-Code. The results of this process are integrated into the Machina's Identity-Code and from there the Machina grows her 'natural' equipment. After this, the Machina almost always expands the capabilities of her equipment by bonding Larvae to it. Simply bonding a Larva to her equipment may only boost the existing abilities, so most Machina will visit a Breeder-class Machina, who are able to accurately apply Larvae to get desirable results when trying to expand the equipment's capabilities. Machina may decide to integrate a captured piece of technology into themselves, which they achieve by first placing a Larva onto the piece of technology, then applying the mutating technology to their body where they want it to be. The Larva on the now-biomechanical piece of technology will establish connections and take over the bonding process, finalizing the connection to the Machina. This is most frequently done by Attacker-class Machina as they capture new weapons and adapt to new situations using them.
Equipment is part of a Machina's body. It is grown from her body, and needs to be supplied with power from her main circuits as well as nutrients from her blood vessels. For these reasons, a Machina cannot remove her equipment outside of certain circumstances. The main way that a Machina may remove her equipment is in a Hive, where she can sit through a process to safely disconnect a piece of equipment and place it on life-support using the Hive's systems. The piece of equipment needs to have a Larva on it to coordinate the disconnection process, and this process can't be safely rushed.
Thrones
All Queen-class Machina have a Throne, which is an evolved form of a regular Machina's equipment. The key difference is that a Throne has its own Core, and as such it generates its own power rather than needing to be supplied with power from the Machina. This second Core can also save a Queen from dying due to fatal damage to her primary Core.. There are two main varieties of Throne: Fusion-type Thrones and Vehicle-type Thrones.
Fusion-type Thrones are still fused to the Machina's body like larger versions of regular Machina equipment. They often have extremely-advanced systems in them that grant the Queen very unique abilities. Like regular Machina equipment, the Fusion-type Thrones are difficult to remove, but can be done in the presence of a Hive as outlined above.
Vehicle-type Thrones are generally even larger than Fusion-type Thrones, and as such can contain even more systems for multiple abilities. As their name suggests, a Queen with a Vehicle-type Throne will ride on or in the Throne, rather than carrying it around like with a Fusion-type Throne. Queens with Vehicle-type Thrones often meld their arms and legs into their Thrones to control them more effectively. This is done by a Larva unmaking the Queen's limbs so they can become like roots within the biomechanical insides of the Vehicle-type Throne. Because of their size, Queens often need to separate from their Vehicle-type Thrones. The Larvae attached to her melded limbs reforms the limbs quickly, and the Queen can pull her limbs out of the Throne as this happens. When detached, the Queen loses the abilities of the Vehicle-type Throne's systems, so many Queens must consider the vulnerability of being detached when they desire the increased suite of abilities afforded by a Vehicle-type Throne. Some Queens have developed the ability to maintain connection to their Vehicle-type Thrones using extendable armoured cables, allowing them to briefly step out of their Throne for sex and the like while still maintaining their connection to their second Core in the Throne.
Interactions with Larvae
Once a Machina has completed development by reaching Category 3, she must grow stronger through other means until she can withstand the application of a new Larva to her body. Once a Larva is applied, she must again build up strength until she can apply another one to her body.
When Larvae are applied to a Machina, one possibility is that they empower an existing organ such as the Core, breasts, womb, or penis, to increase productivity of that organ. Other possibilities include forming redundant organs to help the Machina improve their output or withstand damage, or forming the basis of new organs such as testicles, tentacles or a new piece of equipment. A Machina does not normally see using their Larva eyes, since the multiple streams of visual data is potentially tiresome. However, if a Machina needs to she can expand her visual perception to see through some of the additional eyes. Breeder-class Machina often decide when a Machina is ready for another Larva and assist with bonding it to the Machina's body.
When a Machina bonds with a Larva, that Larva becomes a permanent part of the Machina's body, including the nervous system. Larvae will provide the necessary calculations for operating a part of the Machina's body, such as her Core or operating a weapon system. The Larvae have a very simple mind, but can think for themselves. They send feelings such as 'alert' or 'calm' rather than talk to their host. Should a Larva on a Machina's body find a new person, it consults the Machina's subconscious knowledge to determine what defines a 'friend' and 'foe'. The Larva will then alert the Machina's mind or operate the Machina's weapon based on the Machina's intentions.
As mentioned above, it should be noted that not all extra eyes on a Machina's body are fused Larvae. The Queen's Eye is not a Larva, for example. It is instead a part of the brain-horns complex that helps her handle all the data of her Cluster. Another example is the eye just below the head of a Machina's penis.
It should also be noted that the number of extra eyes on a Machina's body are not a reliable indication of the Machina's power level either.
Machina Mortality
An individual Machina exists both within her own body and within the Main Cluster. If she is a regular Machina, her two halves are linked to each other via her Queen, whilst Queens are linked directly to the Main Cluster. If a Machina goes out of range or loses connection from her Queen, her body will attempt to restore her connection using whatever means are available. The Machina's personality is not harmed by this, but since her personality is simultaneously hosted in both her body and the Main Cluster, the Machina feels a great loss of self when disconnected. The loss of contact causes the other half of the personality to enter a dream state in the Main Cluster until she re-establishes her connection to the Main Cluster. The Machina must sleep extensively to reconcile the experiences of the two halves afterwards, when it is convenient.
A Machina will be seriously disabled if her spine is destroyed, as the majority of her power is transmitted through it, and it provides her Anti-Inertia Field. Due to the complexity and necessity of both the brain and the Core of the Machina, a Machina's body will die if either of these are destroyed. Provided the Machina's brain and Core still function, the Machina can be healed. Light damage often only needs a short time to heal. Moderate damage such as a destroyed limb often requires help from another Machina's breastmilk to heal in a timely fashion. A Machina whose body has been completely ravaged will need to be recovered and sent to a regeneration pod within a Hive to be restored to full health.
When a Machina's body dies, her mind is mostly unaffected. The Queen will upload the Machina's memories to her personality in the Main Cluster, and the complete Machina entity will enter a dream state within the Main Cluster until such a time in the future when the Machina are able to birth new bodies for the deceased to inhabit.