Aura
The hidden power of the soul
As long as humanity has existed, so have the creatures of Grimm. For a long time, the only defences our ancestors had against their natural predator was stealth, their wits, conventional weaponry and eventually Dust.
Then, they discovered the latent power within every human: Aura. Thus did our natural predator became our natural enemy.
Aura is the power of the soul. Such is the tautology that was coined when Aura was first discovered and despite our advancements in understanding, controlling and applying it, it is still the most widespread go-to sentence when one finds himself in need of explaining its nature, despite its deficiencies.
We now know that Aura is not exclusive to humans but is instead a form of energy produced by all living beings: humans, animals, plants. The only beings on Remnant not in possession of Aura are the Grimm, which has only raised more questions about their existence and nature. This is probably also where the animistic tautology related to the Soul originated: once Aura users became trained in its detection and found none in Grimm, it could only be because of their evident lack of a human soul.
While we now know reality to be more nuanced, it is indeed true that humans have a special relationship with Aura, which has made them able to do the unthinkable: hunt the Grimm, turning the predator into prey.
But, if a human gains conscious awareness of the flow of Aura through their body -a process commonly called Unlocking-, they become able to make use of it in a number of ways and also come to know its limitations.
First of all each human being can only produce and carry a certain amount of Aura each day, and this daily amount is called an Aura Pool. Think of it as a water tank that gets refilled regularly. If there's any leftover water in it from the previous day, it will just get refilled for what has been consumed. On the other hand, if all the water in it has been used, you won't get any more water to drink until the next day.
Second, the primary ability of an unlocked Aura User is the Aura Cover, an energy field that simultaneously surrounds and permeates the user's body and provides three primary benefits:
Training also gradually softens the only known adverse side-effect of using Aura: prolonged usage eats into the user's stamina. Experienced Aura users have been known to consume twice the amount of calories needed of a normal human.
Our lacking ability in observing this process has also left us with just hypothesis when it's been necessary to explain why there have been documented cases of Aura users dying from using more Aura than the cap of their pool would allow.
The explanation that's been found is purely theoretical but it does fit nicely into the holes of our knowledge. Just like a body has organs that transform nutrients into energy, the Soul should have an organ that produces and circulates Aura. Let's call this organ the Aura Structure.
Now, what happens if an user found himself with an empty Aura Pool but still forced themselves to produce more? In that case, the theory attests that the Aura Structure would begin to eat into itself like a starving body into its own cells. This process is called Autophagy of the Soul -another inexact tautology but it does work to evoke its terrible effects-.
A body devoid of the Aura Structure dies. Even partially eating into it leaves the User with terrible side-effects, going from loss of mobility and senses to comas to the inability to ever use Aura again (5) .
Then, they discovered the latent power within every human: Aura. Thus did our natural predator became our natural enemy.
THE NATURE OF AURA
We now know that Aura is not exclusive to humans but is instead a form of energy produced by all living beings: humans, animals, plants. The only beings on Remnant not in possession of Aura are the Grimm, which has only raised more questions about their existence and nature. This is probably also where the animistic tautology related to the Soul originated: once Aura users became trained in its detection and found none in Grimm, it could only be because of their evident lack of a human soul.
While we now know reality to be more nuanced, it is indeed true that humans have a special relationship with Aura, which has made them able to do the unthinkable: hunt the Grimm, turning the predator into prey.
AURA POOL AND AURA COVER
All living beings produce Aura and unconsciously release infinitesimal amounts of it daily as they go about their daily lives and, for most of them -including the majority of human beings-, that's where their relationship with Aura begins and ends. It's normally invisible, it has no sound, taste or smell and it can't be touched.But, if a human gains conscious awareness of the flow of Aura through their body -a process commonly called Unlocking-, they become able to make use of it in a number of ways and also come to know its limitations.
Second, the primary ability of an unlocked Aura User is the Aura Cover, an energy field that simultaneously surrounds and permeates the user's body and provides three primary benefits:
- the Aura Cover protects the user: as a suit of armour, the cover absorbs and diminishes all foreign ill-intended damage to the user's body (1) ;
- the Aura Cover strengthens the user: the cover acts as a boosting agent, enhancing the natural abilities of the user;
- the Aura Cover heals the user: any healing process taking place in the user's body is quickened and enhanced;
Training also gradually softens the only known adverse side-effect of using Aura: prolonged usage eats into the user's stamina. Experienced Aura users have been known to consume twice the amount of calories needed of a normal human.
OTHER ABILITIES
There are a number of other abilities that are granted by an unlocked Aura which are not, though, automatically learned and must be discovered and refined through training (3) .- Precision Enhancing- an user may learn to further enhance certain aspects of their persona, like the strength of a body part, the sensitivity of one's own senses, the body's capacity to dispose of toxins or the capacity to sense the flow of Aura in others;
- Item Enhancing - provided the item is made of a special material, an user may treat it as an extension of their own body and cover it in their Aura;
- Dust Interaction - an user may use Aura to activate Dust Crystals and/or power Dust based devices;
- Semblance - a Semblance is an unique skill ability exclusive to each user (4), with effects that go from the simply physical to the esoteric. Usage of a Semblance dips into the user's Aura Pool;
THE SOURCE
The tautology of the Soul is accepted because of the lack of any reasonable alternative. We've been able to quantify Aura, observe its effect on its users and targets but we've never been able to observe the act of producing it, the filling of the Aura Pool, how it circulates. Even if we don't believe Aura to be a product of the soul, it does not come from the body.Our lacking ability in observing this process has also left us with just hypothesis when it's been necessary to explain why there have been documented cases of Aura users dying from using more Aura than the cap of their pool would allow.
Now, what happens if an user found himself with an empty Aura Pool but still forced themselves to produce more? In that case, the theory attests that the Aura Structure would begin to eat into itself like a starving body into its own cells. This process is called Autophagy of the Soul -another inexact tautology but it does work to evoke its terrible effects-.
A body devoid of the Aura Structure dies. Even partially eating into it leaves the User with terrible side-effects, going from loss of mobility and senses to comas to the inability to ever use Aura again (5) .
"Strangely enough, there's no such thing as 'the person who first discovered Aura'. Unlike other knowledge and skills which originated in a specific location and period and then got spread through Remnant following trade routes, Aura seems to have popped up a bit all over the world roughly around the same time. It feels less like someone discovered it and more like someone suddenly flipped a switch..."~Tai-Yang Xiao Long
FOOTNOTES
(1) Aura has not been found to protect the user from things like damage done through physical exercise or when undergoing surgery or, sadly, when attempting suicide. For better or worse, Aura is closely tied to the wishes and personality of the user.(2) The refill process of the Aura Cover can be hastened by the user's consciously focusing solely on the process. Some chemicals have been also found to trigger the process when injected. In either case, the user will be unable to use his Aura for anything else as the refill happens.
(3) The safest unlocking method is to force a small amount of an unlocked user's Aura into a locked user's body. The recipient will automatically unlock his own Aura to flush out the foreign one. Failing that, it's been observed that stressful and/or traumatic events may lead to an unlocked state. This method more often than not also activates the user's Semblance so there's an accepted theory that the former is a consequence of the latter.
(4) There have been rare cases of a Semblance being passed from parent to child, and even rarer cases of the same Semblance being transmitted over numerous generations. One notorious example is the Schnee family from Atlas.
(5) There have been no recorded cases of involuntary or induced Autophagy of the Soul, the process must be initiated by the user itself.
