The entire dimension of Duamutef consists of several dimensions connected to a central one. The "Prime" dimension consists of a single galaxy that is the de-facto center of the universe--the other realms are essentially attachments which are interconnected through this central realm, though they also hold numerous connections to one another. The creatures that inhabit the Prime galaxy and it's thousands of planets and stars are infinitely varied and diverse, but the vast majority of them share one common characteristic--they eat other creatures whole. Several other unusual traits are shared between most creatures, not the least of which is their genetic structure and means of reproduction.
Some say Duamutef created the universe as an experiment, and some say it was practice for his aspirations to become a greater god. And some say it was merely an outlet for his own perverted fantasies. No one knows.
(Though just between you and me, it's that last one.)
The universe as it is now consists of five realms, each of which is essentially a separate plane or dimension. These realms are Phaesili, Beastspace, Brightwind, Faneglut, and Prime.
Prime consists of an immense cloud of stars interspersed with planets, energy forms and other celestial objects. These objects do not 'orbit' one another per se---though they do tend to congregate, most of them are not actually mobile, and therefore a planet may be able to claim five or six primary stars as it's own, whereas any given star probably has a good view of dozens of planets. Conversely, however, planets and stars are infitesimal in size compared to the more familiar bodies in our own star system--many of the smallest planets in Prime could be crossed in their entirety in just a few hours of walking. There planets which are of significantly larger size, measuring hundreds or even thousands of miles across, but most are dwarfed by terrestrial planets and planetary bodies on the scale of gas giants and the like are almost unheard of. While they do exist, they are extremely rare. A typical planet in Prime only a few hundred miles in diameter, and many are as little as a few dozen. (Such planets are often referred to as moons, though they do not orbit larger planets as moons in this universe do.)
One of the most drastic differences between this universe and Ishara is in it's treatment of living beings. Spirits have physical substance, and the way creatures perceive the world is fundamentally different.
True suffering is practically impossible--the mechanisms that bind awareness with sensation are designed to be all but incapable of it. Though there are physical sensations resembling pain, they are invariably 'good' pain. The creatures in this realm are unique in that they actually have physical 'spirits' which house their consciousness and serve as an intermediary between their essence (also referred to as their "soul") and their body. These spirit-bodies have myriad capabilities, including the ability to protect or regenerate whatever physical vessel they inhabit instantly or near instantly, provided they have the necessary energy. The energies of the body are innately tied to the energies of the spirit, and thus it is very difficult to truly 'injure' a body that has a spirit in it. The stroke of a sword may end in a flash of light but no injury. The reason for this is that the spirit always preserves the body--it can phase out certain parts, restore others, and is essentially capable of keeping the body fully intact so long as it has the energy to do so. (This energy supply is analagous to a creature's "Hit Points.") The spirit has a limited store of this energy, however, and when it runs out, it must exert itself much more than usual to restore the body--leaving it too distracted to do anything else, such as move. With an exceptionally strong spirit, however, it takes a constant source of damage to overcome it's regenerative abilities. Generally, the only thing that can constantly damage a body are things like fire and acid, and some spirits are strong enough to withstand such constant damage unless something is actively stopping them. There are few things capable of stopping a spirit from restoring it's body, but one of those few things is actually very common: the digestive tract. The digestive tracts of Isharans are capable of absorbing certain spectrums of spirit energy, including the ones necessary to repair physical damage. While they will not necessarily absorb all of the energy put out by a spirit body, the constant damage combined with the fact that the spirit body will have no way to renew it's energy reserves (any energy it could absorb is already being absorbed by the creature that ate it) will eventually deplete it, allowing the physical body to be destroyed. Conversely, a spirit that is efficient enough can often keep a body functioning using ambient energies alone. Thus, with a strong enough spirit-type, a creature can only be killed by being digested. Most higher beings (intelligent monsters, humans, demons, angels, fae, etc.) possess spirits strong enough to do this, though the degree and efficiency with which their body is preserved varies.
Different creatures have different spirit-bodies and the regenerative capabilities of each vary greatly. The creatures generally called 'Monsters', for example, have average regenerative capabilities, whereas the humanoid races of the central dimension have regenerative abilities so powerful that they are often unkillable by any means other than digestion. (In their case this has more to do with their spirit body's energy efficiency than their actual energy reserves.) Even the weakest spirit can instantly restore damage while they still have the energy, however, so even the weakest monster will not suffer any significant injuries until their energies have run out.
This is not to say that injuries are never sustained. Spirits are pragmatic, and will only repair superfluous damage (minor cuts, bruises, and the like) if they have a large store of energy. If they are critically short of energy, on the other hand, they will only repair life-threatening injuries, meaning someone who has been in combat for a substantial period will start to accumulate wounds of ever increasing severity. This will go only so far, however; if an injury is lethal and the spirit body cannot repair it, the spirit will typically reverse the flow, taking energy from the body and subsequently leaving it, resulting in "death."
Spirits have different triggers for leaving their body--with monsters, they often leave the instant they suffer a serious injury that they do not have the energy to heal, since it is unlikely that they will gain enough energy to repair it anytime soon. With others, particularly girl races, they won't give up until their entire body has been annihilated beyond all hope of repair. The faster the spirit regains energy and the less energy it takes to heal, the more resilient and resistant to injury and death the creature will be. Even with monsters and other weak spirits, it can take a whaleload of damage to kill one. It is often more expedient to eat them, even if they're still struggling (and while a body may not be dead, sustaining damage will still weaken them).
In any case, a spirit that has jumped ship generally seeks a new body afterward. Reincarnation is the rule of the house in this universe--monsters often enter a new body almost the instant their old one is killed, and many girls observe only a short period before they are born into a new body. (Though some choose to hang out in the afterlife for a while, if only to socialize.
Nearly all 'magic' is based on the spirit--it converts ambient energies into 'mana', which is actually a highly mutable form of physical energy (or, more specifically, a spectrum of such energies), which it stores for later use. When a person wants to cast a 'spell', the spirit metabolizes this energy and alters it into the form that it's master wishes. The spirit gets better at this with practice, so merely using magic tends to gradually make it easier. Besides the strength of the spirit, the intelligence and fine mental control of the caster can go a long way towards creating greater magic as well. Without a spirit, no creature can use magic, and some spirit types are incapable of producing it. 'Magical energy' is actually a catch-all term for all the forms of etheric energy, most of which aren't actually 'magical'--there is a huge spectrum of energies that do not interact on the same level with physical energies, or interact in ways that are more subtle than normal, kinetic interaction. In the most utilitarian sense, the only energies that are truly 'magical' are those formed by mana through a spirit, but since even those energies are indistinguishable from others in any other way, the term 'magical energy' refers to most energies that aren't as obvious as physical 'matter'.
Some 'spirits' are larger than others--in fact, planets and even the stars themselves have spirits, and indeed, they also eat, though most denizens do not know this. Planets typically nourish themselves through plant life. The carnivorous plants that fill the jungles and wastelands eat to sustain themselves, but also pass part of this energy on to the planet. Not all plants share this relationship, but most do. Some planets will even abandon subtlety and eat other creatures directly--many a girl has been surprised indeed to find herself sinking into a deep bog which subsequently starts digesting her. Thankfully, the immobility of most planets means they do not need to eat nearly the same proportions as a 'living' creature, and thus epidemics of girl-eating bogs and odd-looking slippery crevices decimating planetary populations are not common. On most planets the plant life and ambient energy is sufficient and on others a snack here or there is all it takes, maintaining the illusion that planets do not eat.
All things in the dimension are based on the same energy cycle--things devour, taking the energy of other things, then are devoured themselves and give up their own energy in turn. This process is intensely pleasurable for both parties in all cases, though it may take them a while to realize it. Though most creatures have an instinctual feeling that being eaten is scary and gross (being necessary as a basic survival instinct), those few who survive it more than once actually have a pronounced tendency to get addicted to it. The fact that most girls have a secret fascination or attraction to the grossness of it even before they've tried it also escapes the notice of society at large; in essence, everyone has the same embarassing secret fantasy about being eaten.
Most creatures only digest the body, but a few (particularly 'ghosts' and similar creatures) actually digest spirits as well. This isn't as horrific a fate as it sounds--the spirit is merely a vehicle, albeit an etheric one. Like bodies, when a spirit is lost, it is merely replaced with a new one. In essence, the actual consciousness of the creature is separate from the 'spirit'. When the spirit is digested or destroyed via other means, the consciousness is furnished with a new one.
Both the spirit and the body have capacity for memory, although they are of differing precision. The two normally work in tandem, meaning when a body is destroyed, many of it's more detailed memories are lost, but echoes of them will remain in the spirit body. Since the lifespan of an average creature is measured in years at best and minutes at worst (despite the lack of "natural" death), this means most people will have vague memories of many past lives, though they rarely seem to be all that important--since they will inherit not only spiritual memories but also strong genetic memories from their new bodies (explained below), the vague memories of a plethora of past lives are rarely motivating; they tend to blur together and are sometimes even contradictory, so individuals tend to go with whatever their current identity wants rather than what their past agendas may have dictated. When the spirit is destroyed, most of the remainder of these memories are lost. (The dimension does maintain it's own equivalent of the Akashic Record, however--a great repository of the experiences of every creature ever to live, which is accessible to spirits at certain times, particularly when they are not incarnated in the 'physical' world. This allows spirits to gain a "Fresh perspective" on life by shedding old memories from time to time.)
To compensate for this rapid recycling of memory, nearly all creatures have a set of core memories that come with each new body--these are essentially elaborate sets of instincts which instruct creatures on how to speak, hunt, defend themselves, and even cast spells. Though you may not remember your past life, you will still know how to talk, identify predators, and perhaps even forge weapons or build engines. Many of the social castes among humanoids are actually genetic in nature; a girl describing herself as a 'huntress' may well have been born with a different set of instinctual skills that make her more adept at hunting monsters than others.
As a general rule, all creatures are born with the capacity to operate in whatever society they were born into. These genetic memories are even mutable through different generations, giving newborns a sense of current events and local geography. New bodies tend to take some of the memories of surrounding people (These are always non-personal memories, such as skills and knowledge), so that when, for example, a particular member of a clan gets extremely good at making enchanted gems, there will be more girls born who are subsequently naturally good at making similar gems. In this way, genetic groups tend to specialize, with newborns having knowledge and skills that are similar to their forebears. So although memories tend to be lost quite frequently, every newborn life is essentially an elaborate continuation of a previous life, with a new identity and possibly a different set of skills.
Due to these unusual spiritual dynamics, lifespans are often measured by spirits rather than by bodies. It is considered normal that old friends are digested and reborn, and spirits are often capable of recognizing one another despite changes in the body (which manifests as an intuitive knowledge that a newborn stranger is actually an old friend). Losing a spirit simply means moving on to a new persona, allowing people to experience all possible aspects of the universe--a girl who has her spirit digested may end up reincarnating as a monster, allowing her to experience life from that point of view. (In fact, often a soul will switch spirit bodies before the existing one is even destroyed.) Girls in the afterlife will have access to the memories of everything they have ever experienced, and they will sometimes intentionally bring select sets of these memories with them when crafting new spirit bodies for themselves.
Physical laws would appear familiar to Earth people, but only to a point. While Isharan physics creates many of the same behaviors on the surface, physics as a whole do not behave the same way, nor do many of the more advanced or esoteric precepts of science. Gravity, motion and distance seem similar on the surface, but in truth work very differently. Put simply, the Isharan universe as a whole is physically different on a fundamental level.
The energies that compose the universe of Ishara are not the energies familiar to Earth people. There are more of them and they are more mutable; where our universe contains only a few kinds of primary matter that typically behave in a single, consistant way (protons, neutrons, and electrons, for example), Ishara has dozens, most of which have a spectrum of behaviors and, indeed, a spectrum of states that alter those behaviors. These different energies mean that the 'biological' processes contained in all of it's creatures are significantly different than normal, though on the surface they may also look similar. Existance in Duamutef's realm would seem familiar to Earth dwellers, though it would not take long before an Earthling would start noticing the often drastic differences.
Matter in Ishara comes in many different varieties, though most of these are interrelated and can be converted into one another. For example, physical matter, spiritual matter, and magical matter are considered distinct (and they are, in many respects) but all three are simply different forms of base matter. The relationship between physical matter, mana, and spirit matter could be compared to the transition between solid, liquid, and gas.
On Earth, matter has a one-dimensional phase range; there is only one thing that determines the phase of matter, which is temperature. Isharan matter has a more complex nature. Isharan matter has three simultaneous phase states; one for it's physical phase (solid, liquid, gas), one for it's "frequency" for lack of a better term (for physical matter this determines what kind of matter it is, similar to an element's atomic number) and one for it's etheric phase (which is determines which other etheric phases it interacts with).
In addition, matter has five basic physical phases rather than four. Normally there is solid, liquid, gas, and plasma. Ishara adds light to the beginning of this spectrum; rather than having photons, light is simply matter that is not massive enough to have substance (thus it is "below" solid. If light gains enough energy and intensity, it condenses into matter). After solid, liquid and gas, there is something similar to plasma, but it behaves more like terrestrial fire (it is what the locals refer to as fire; what they call "plasma" is actually an elemental liquid).
In addition, these phases cycle into higher forms once an object's energy level exceeds that of fire; when fire is heated sufficiently, it changes into a second, more energetic form of light. Likewise, when this second stage of light is heated enough, it gathers into a second stage of solid matter, and so forth. Were you to obtain enough energy, you could push it further into a second level of liquid, a second level of gas, a second level of fire, and on into a third level of light; in fact, it can be done indefinately in theory, giving Isharan matter an infinite number of material phases. When matter rolls over from fire to light, it loses it's heat; it's heat energy is converted into mass as it transitions into the new form of matter. The same is true when light transitions into a solid; most of it's energy is converted into solid mass.
Isharans actually believe there are six kinds of matter; Earth, Air, Water, Fire, Light, and Dark. Light and Dark are actually both forms of second stage light; it is essentially light that has more mass and energy than fire, but because it behaves as light, it does not necessarily impart this energy as fire would; instead it's mass permeates an area just as light does, but because it has mass, it can obscure or block light at low energy levels (elemental dark), whereas it can exert physical force at higher energy levels (elemental light). It can also carry more magical energy than normal matter since it is technically more energetic than standard matter.
Other second-generation phases of matter are also called Elemental matter; matter that has been pushed beyond plasma and subsequently pushed beyond second-generation light would be called an elemental solid. They are inherently more energetic than first-generation matter phases, and this gives them altered characteristics; besides absorbing more energy and being more massive, they are also more mutable and fluid, with the exception of crystallized forms, as crystallization causes matter to use it's additional energy to maintain the crystal lattice, making them harder than a first-stage solid of the same type is capable of being. Blades made of elemental Earth--i.e. crystalline second-generation solids--are extremely good at cutting through armor, since normal solids won't have the energy or density to prevent the blade from penetrating it. (This is not to say they penetrate any and all armor effortlessly; they are simply far better at it, all other things being equal. Elemental matter comes in blunt and soft varieties, just as normal matter does.)
The reason second-stage matter is called "Elemental" is because it usually only occurs as a result of magic. It is very difficult to impart enough heat energy to move matter past the plasma stage; this is simply because the dark/light phase in each generation acts as a gap. Since elemental dark is actually colder than normal fire and light doesn't interact chemically with normal matter, it is almost impossible to heat it. (Building a fire inside a field of elemental light isn't going to heat it up, so it won't gain enough energy to coalesce into an elemental solid.) To do so generally requires imparting the heat in another way; most of the time, this is by giving it energy from matter that is in a different etheric phase. Altering an object's Etheric state also changes the energy requirements needed for it to change phase, so translating a physical object into a magical object may also change it from a physical liquid into a magical solid or vice-versa. The different etheric phases of matter are the basis of magic and are the only means most creatures have of ever creating matter of a phase higher than first-stage fire. (There are a few technological means to create second-stage matter, but they usually require heating something so much so quickly that it skips the elemental light stage completely and moves into elemental solid or further.)
There is a third stage of matter just as there is a second. Third stage light is used in transmutation and infusion magics; it has enough energy that it can actually affect lower levels of matter even though it is only light. Third stage light alters the frequency of matter within it's field, causing it to increase or decrease. The process of transforming Gold into Lustrasteel is a simple form of this; the gold gains energy from the third-stage light, eventually causing it to shift from one frequency (the frequency that composes "Gold") to another (the frequency that composes Lustrasteel). That's also why very powerful transmuters can turn just about anything into Lustrasteel without even using gold; provided they have enough mana, they can simply saturate it with third-stage light until it matches the desired frequency.
Though they don't realize it, the creatures in Ishara all have some level of third-stage matter inside their bodies; specifically, the stomach and intestines are laced with third-stage matter. This is what gives them their reliable elasticity (third stage matter being even more fluid than second stage) and near-indestructibility as far as weapons are concerned, since even an elemental weapon will be at least a full stage below it in energy phase. Attempting to break through a stomach with a weapon forged of elemental steel is akin to trying to pierce through armor with a handful of water, and attempting it with a mundane weapon is like trying to pierce steel with air.
Unfortunately for them, virtually no Isharan is capable of intentionally creating third-stage matter higher than low frequencies of light; in fact, few even know of it's existance; most Isharans believe that physical matter only comes in two varieties (normal and elemental).
In addition to it's physical phase and frequency, matter has an Etheric phase. Like physical phases, there are five Etheric matter states: physical matter, magical matter, arcane matter (better known as mana), spirit matter, and void matter. Unlike temperature phases, however, etheric states do not have stages (though matter will still have a temperature phase and stage, regardless of it's etheric state; for example, there are second-stage arcane liquids).
Physical interactions between the five etheric matter states are limited; each is capable of directly interacting with other matter in the same state and the state immediately below it, but cannot act on states above it or more than one level below it. Physical matter is the lowest etheric state, whereas void is the highest. Thus, spirit matter is "solid" to other spirit matter and to arcane matter, but not to magical matter or physical matter, and interaction between arcane matter and spirit matter is one-way; spirit matter is solid to arcane matter, but spirit matter is not affected by arcane matter. Arcane matter is solid to magical matter in turn, but magical matter is not solid to arcane matter; arcane matter can freely pass through it or displace it without expending any energy.
This is not to say matter can never affect matter above it; an object's Etheric state is an energy state, much as it's phase is. Matter that gains enough etheric energy will naturally transition physical to magical, from magical to arcane, and so forth. What's more, while matter is not solid to energy states above it, it does tend to be "magnetic;" if matter from one stage overlaps matter from another (particularly matter of the same phase and frequency) they will become bound together, causing the higher stage matter to move alongside the lower stage matter. Since the matter immediately above any given stage will be solid to it (and thus will stop it from overlapping), it means that very high energies tend to follow very low energies (arcane matter usually ends up integrating itself into physical matter, spirit matter ends up integrating itself with arcane matter, and so forth.) This is why most physical matter contains mana (which is really just arcane matter). In fact, since physical matter is the lowest possible phase, it is usually what higher energies become bound to. Binding only occurs when energies are of similar frequency and phase, however, and dense concentrations of matter of the next lower etheric state tends to act as a buffer.
Phase temperatures tend to either be multiplied or divided geometrically when etheric state changes, depending on the matter's frequency. Most materials will lower their phase temperatures; a particular kind of matter stored at room temperature may be solid in it's physical state, liquid in it's magical state, gaseous in it's arcane state, and elemental light in it's spirit and void states. (If it's phase temperatures are lowered enough, it can even become second or even third stage elemental matter.) Other materials do the reverse, increasing their phase temperatures, causing them to solidify as their etheric state rises.
Some frequencies of matter remain the same as their etheric state changes, meaning they will be the same material; physical adamant that transitions into an arcane state will be arcane adamant. The physics of matter changes with etheric states much as they do with temperature phases, however, meaning arcane adamant will not necessarily behave identically to it's physical counterpart.
"Magic," the act of casting spells, enchanting items, and otherwise altering the world through mystical means, is actually achieved through the interactions of different etheric states. Living creatures have both a physical body and a spirit body. The spirit body is a combination of spirit matter and arcane matter; casting a spell is a biological process of sorts, with the spirit matter controlling and directing the arcane matter in order to create and alter lower-level energies (both physical and magical).
The spirit body's arcane components are composed of both first and second stage arcane matter. The second stage matter constitutes the permanent sections; those that aren't meant to be converted or spent in the process of creating spells. They are made of second stage matter in order to prevent enemy mages from simply destroying them using their own magic; the spirit body is generally incapable of creating second-stage arcane matter on it's own, with the exception of second-stage light.
It's spirit components consist primarily of simple, first-stage spirit matter, with a few core components consisting of second stage matter. The major exception is creatures that are capable of "digesting spirits;" though almost all creatures contain stomachs made of spirit matter, it is usually first stage and thus only capable of digesting the more basic components of their prey's spirit body. Those that can digest spirits, on the other hand, have second-stage spirit matter in their stomachs and use it in much the same way that physical stomachs do. The major difference is that with normal spirit stomachs, the core components of the spirit body--those made of second stage matter--survive, whereas with advanced spirit stomachs the core components are digested along with the rest.
Different species, particularly species of different archtypes, have other unique traits.
Human spirit bodies have a small but elaborate chain of second-stage matter of every stage, and theirs are among the few spirit bodies that consistantly contain magical matter. These extra structures are dedicated primarily to preserving their physical body, and it accomplishes this quite well; when all else fails, it is capable of temporarily replacing parts of the physical body with magical matter, which cannot be harmed directly by physical matter. This cannot restore failing biological functions, however (while magical matter is solid to physical matter, the reverse is not true, so the interactions necessary for biochemistry are usually). Thus, it's usefulness is limited to keeping the person intact enough that they can survive until they can regain enough energy to repair their physical body. (While biochemical processes won't work, magical matter can prevent blood loss, replace bulk tissues such as bone and muscle, replace broken bones, pump blood, and fulfill other simple structural needs.)
Demons have an altered version of this; instead of having spirit mechanisms designed to repair their body more effectively, they have a certain amount of magical matter in their bodies that is maintained by their spirit body. Like with humans, this matter is in places where biochemical processes are unnecessary or when they can be self-contained. Most demons have bones that contain an inner core of magical matter, and their muscles are likewise laced with magical matter. This means that regardless of the damage they take, demons cannot have their bones broken by purely physical means, and their muscles can be fueled directly by their spirit bodies, making them considerably stronger.
At the far extreme of this lie Elementals and Ghosts; these creatures have bodies made either primarily or completely out of magical matter. This means nonmagical weapons will either inflict limited damage or none at all. However, it is very difficult to survive when limited exclusively to magical matter (for one thing, without physical matter, they can't perceive physical light), so most Elementals and other magical creatures are still composed at least partially of physical matter. Only ghosts and other apparitions are mostly magical matter, and these creatures must also feed on higher stages of matter.
Other Fae creatures have magical matter in their bodies as well. Though it is not nearly as much as magical creatures such as Elementals, it is still important to their bodies, as they actually do use magical matter for some of their biological processes. This gives them numerous abilities, which vary by species.
Angels have stronger spirit matter in their spirit bodies; while the arcane matter is normal, most of the spirit matter is second stage (the only exception is their stomachs, which are usually normal). This means that digesting an angel inflicts no damage on their spirit body; this is why they are able to reincarnate the entirety of their original body when they are eaten.
Lastly, there are monsters. Monsters have few spiritual advantages, but this makes their spirit bodies simpler to grow. This drastically cuts down on the time it takes a monster to hatch from it's egg.
...do not exist.
Matter can attract other matter in a variety of ways, however. This usually occurs when a block of matter is being pushed against by matter from the next higher etheric state, but, for whatever reason, cannot move in response (if a solid is being pushed against a wall, for example). If this is the case, the force that would normally have been applied to the object is diverted to other nearby matter. This generally results in attraction, repulsion, or acceleration along another vector (similar to magnetic force) according to the matter's frequency, phase, and etheric state. In most cases, when a gas undergoes this effect, the effect is to repulse other matter (which is part of the reason wind magic exerts a surprising amount of force). When a liquid undergoes this effect, it accelerates matter along a rotational vector (which is what gives water magic it's natural tendency to cause whirlpools when used in actual water). When fire undergoes this effect, it accelerates matter in whatever direction it was already moving, whereas when a solid undergoes this effect, the result is to attract other matter. This is why creating large physical structures using Earth magic is comparatively easy; it is also the reason "gravity" exists.
These accelerant effects are normally fairly weak unless they are at short range, but planets generate a fairly strong field; one that is strong enough to be comparable to gravity, though the mass required to create the effect is a tiny fraction of what it would be for genuine gravity. The reason planets generate such a strong field is that planets have spirit bodies, just as normal creatures do. However, unlike normal creatures, planets are primarily solid matter, and their spirit bodies contain a high concentration of solids from every etheric state. Thus, as their spirit bodies perform their functions, they constantly grind these solids against one another, causing a huge amount of etheric "friction" that causes matter to be accelerated towards them.
There is a fairly strict limit on how much force can be applied in this way, however. The inverse square law applies not only to range, but also to total acceleration via this force. If matter is already undergoing a certain type of acceleration (attraction, repulsion, or vector), it is much harder to accelerate it further using that same type; it becomes "saturated" and increasingly resistant to that particular force. This means even enormous planets will only have slightly more gravity than small ones. Closeby matter also exerts it's effects sooner than distant matter, so an object on one planet will typically be too saturated to be affected by another even if it is very closeby.
Each type of acceleration is distinct; the attraction from a planet may negate the attraction from another, nearby planet, but it would not reduce the repulsion from an air field or the vector acceleration of a water field. Because gases repulse and solids attract, planets tend to hug creatures to their surfaces; the atmosphere pushes them towards the ground while the ground pulls them. This also means one of the biggest determinants of a planet's "gravity" is not it's size, but the thickness of it's atmosphere. (Like size, however, it reaches a point where more mass will not increase the force any further.)
The one way gravity can be increased significantly is by increasing the amount of second or third-stage matter on a planet. Second and third stage matter exert considerably more force than first stage, and this can cause a planet to exert much stronger gravity.
The natural tendency of etherically displaced air to repulse other matter is part of why there is no "space" in Ishara (or, more specifically, space is not a vacuum). The space between the planets contains plenty of air; just not as much as a planet's surface would have. When combined with the fact that most Isharans do not need to breathe to live, this means exposure to deep space will not cause significant harm to a person. (At least, not on it's own. As it turns out, space is infested with monsters, and this is what kills your typical unprotected astronaut...)
The balance between the repulsion caused by gases and the attraction caused by solids is also the reason planets and stars do not form orbits; while planets are composed primarily of first-stage solids, stars are largely composed of second or third-stage gases. This means planets and stars form a web of attracting and repelling forces, holding one another in place. (It also means it takes considerable thrust to enter a star, as they exert powerful antigravity.)
There are countless technological uses for this phenomenon, and it forms the basis for many fundamental starship technologies. It makes both artificial gravity and antigravity almost effortlessly easy; either can be created with nothing more than a device that pushes matter from from one etheric state into another (solid matter for gravity, gaseous matter for antigravity). The same can be used to create deflector shields (by using liquid matter) and can even accelerate projectiles (via fire matter). A basic starship can be built using nothing more than these simple techniques.
Even so, most Isharans aren't scientists, and typically only people born with the Engineer birth class will know how to build these devices, and many will know how to build them without even knowing how they work. Those factions who do have a decent understanding of Isharan physics (such as large spacefaring empires) are capable of building all manner of devices, from elemental matter converters to interdimensional portals. Those who understand the true nature of both physics and biology (particularly spirit biology) can become unimaginably powerful, and it is from these ranks that the majority of void mages (and void mage trainers) come from.