Aura and Semblance

Every living being produces an energy known as essentia; the energy of the soul, unique to each individual, and one of the main and most powerful weapons in the war against the Grimm. It is a quantifiable and unique energy, able to be both measured and its source identified against a known database. Aura and Semblance are different manifestations of this energy, and draw from their user's pool of essentia to use. Essentia can be compounded with potentia for greater and more varied effects, both within aura and semblance.

Aura is a physical manifestation of essentia, . While all creatures have aura, its manifestations - such as protecting the user, healing others, or even attacking their opponents - are all known as 'aura arts'. While aura does not need to be unlocked, any manifestations of it must be learned, taught, or figured out by the use; the knowledge is not instinctive. However, anything with aura can learn to utilise it - even animals can be trained to wield it.

Semblance, however, cannot be taught like aura arts. They are an aspect of the user's soul unique and inherent to the individual, granting them an ability often outside of the normal boundaries of aura and potentia. Semblances often aren't one ability; rather, they are more of a *concept*, allowing the user abilities under that concept in a common and uniform theme. For example the semblance Polarity allows its user not just to magnetise objects or to control magnetic substances, but to also magnetise the user's feet to surfaces, both magnetic and not; or to charge an opponent's wooden club and their nose with the user's essentia and cause the two to become attracted to each other, hitting them with their own weapon. Like aura, semblance can draw from the user's essentia if necessary, but they also have their own buffer of energy. They are also rare; most of the population does not possess even the potential to unlock a semblance; they simply do not have one.

Semblance are, in a way, alive in their own right - when first triggered by someone with the potential to use one, they appear to the user in an out-of-body experience as time slows to a crawl. The user is faced with a figure; often a mirror of themselves, but sometimes an avatar that represents the semblance. If it is a cooperative semblance, it will introduce itself, while an uncooperative semblance may stand staring at the user, or mock them. Either way, when time resumes, the user knows they have a semblance - and if it introduced itself, they can use it right away. After the first trigger, facing the semblance again will require similar triggers, bringing the user to the same out of body experience. Triggering this process too often can cause damage to the user's soul, so it should be used sparingly. However, their user is always aware of the semblance after their first trigger, and can vaguely communicate with it. For example, it may be a whisper in their ear warning them of dangers unseen; a flash of warmth when the user is feeling down; a pull into soul space for a simple chat and catch up; or even actively antagonising the user in their dreams. Furthermore, semblances can be aware of the user and their surroundings, though the degree varies from semblance to semblance. Unlocking an uncooperative semblance is often a process unique to each individual, and because the same semblance might appear frequently or may even be hereditary, details are often recorded and researched.

There are five tiers of semblance, indicating the semblance's mental willpower. Stronger-willed semblance are not necessarily more powerful; they are simply harder to control. There could just as easily be an animal semblance that is terribly destructive and powerful as a royal semblance with a comparatively weak, simple effect, which the semblance simply refuses to allow the user to wield. The categories are, in order of mental willpower from lowest to highest:

* Animal: Animal tier semblances are nothing but raw instinct. When triggered, the user instinctively knows their name, and the semblances do not communicate with their user.
* Child: Child tier semblances have a simple spiritual presence and a trusting personality, immediately introducing themselves.
* Warrior: Warrior tier semblances are the middle tier of semblances. They have a more complex personality, similar to noble and royal tiers, and a greater willpower than those of child and animal tiers; however, they do not have a title. Warrior tier semblances may disagree with their user, challenging their decisions, but most ultimately work for the benefit of their user and grant them their name from the beginning, if having to complete a task first to prove themselves. Furthermore, forcefully using the semblance is more easily possible if the semblance is refusing to lend its power to the user in comparison to noble and royal semblances.
* Noble: Noble tier semblances have the second greatest willpower, and are the first tier to possess a 'title'. While all semblances are named, noble and royal semblances possess a further title to their names that must be learned for the user to wield it. Titles are uniformly a type of mission statement, a boast about the semblance, a motivation to the user, or a threat to the enemy.
* Royal: Royal tier semblances have the greatest spiritual presence. Like noble semblances, they possess a title; however, their willpower is even greater than that of noble tier semblances, to the point where forcefully taking control is incredibly difficult, if not impossible, even with an iron will and unwavering determination - instead, the user must come into an accord or a harmony with their semblance in order to fully utilise it. If not, they may not be able to use their semblance, barring extreme circumstances - or they may have their semblance forced upon them every waking moment.

There are also two types of semblance. An average individual is most likely to have neither of these types, but it is possible to have either or even both.

* Individual: Individual semblances are semblances that randomly manifested. They are semblances you have 'for being you' - the effect of it based on your character.
* Associated: Associated semblances are semblances you possess because of your bloodline, culture, where you were born/grew up, things you did, or even from contact with a Fey - they are semblances that choose their wielder based on any number of these categories and more. Some are known to be bloodline-bound, some are talked in myths, others a known fact but unknown how they choose their owners. It isn't possible to manipulate this 'choosing' process directly either.