Auras

What are auras?
Auras are required to perform any type of non-physical technique. There are four types of auras, each in charge of a particular category of techniques. Auras cannot be seen with normal eyes. You must have angelic eyes (eyes of an Angel or Fallen Angel) to see them. Humans, aura crystals and ores all contain auras. Only humans and purified "Aura Crystals" radiate a significant amount of auras.
 * Black aura - Catabolic
 * White aura - Anabolic
 * Green aura - Creative
 * Purple aura - Psychological

Auras and People
People are born with a set amount of auras, and parents put kids into classes usually based on what their natural aura composition is. People can consciously radiate aura without performing a technique. However, this act alone does not do much, and most people can't even see it happening without angelic eyes. However, radiating aura consciously can act as a support for another person performing a technique using the same aura type.

Small amounts of auras are constantly being radiated subconsciously even without a person trying. Some say that aura can be "felt", like a vibe that a person gives off. When someone gives off a "good vibe", it's is probably because they have a favorable aura composition.

Aura Elevation
Auras of an individual can be unnaturally boosted/elevated to a higher level with the help of some illegal techniques and aura cyrstals. Elevating an individual's aura unnaturally is like giving them much stronger muscles without giving them stronger bones and tendons to properly support the stronger muscles. Thus, while the individual has more aura, the rest of their body can't keep up with it therefore they end up losing control and hurting themselves or others. One must train endless so their body can become better at controlling this new chunk of aura. However, because this is an unnatural process, the body will never be able to fully control and properly use the extra aura that it's not meant to have.

Aura Hotspots
An aura hotspot can be created using crystals or by having other individuals consciously radiate aura towards a concentrated area. Being in an aura hotspot allows an individual to perform techniques they're usually are not able to, or to perform a technique at a much higher magnitude than they're usually capable of. Using aura hotspots is very different from aura elevation. Using an aura hotspot is like using a powerful human-body controlled machine: it makes and individual's movements much stronger even though the individual is using the same amount of strength and the user's body is not altered in any way.

Nature vs Nurture
All individuals are born with at least traces of all 4 types of auras, but the amount of each of the 4 types an individual has is different. If 100% is the maximum amount of a certain type of aura that a body can possibly hold, then the maximum amount that one can gain purely through growth (by nature) is 50%. An individual can gain another maximum amount of 50% each type of aura through training (by nurture). However, it's very rare for someone to reach their full potential by gaining all 50% of the aura that they can gain through training.

Example: A person can gain 5% black aura through growth, then the maximum amount of black aura this person can ever have in their lifetime is 65%. This is by gaining 50% black aura via training + 5% black aura by nature.

Auras and Techniques
Auras are required to perform any non-physical technique. The kinds & amount of auras required depends on the technique. The auras themselves are not used up through performing techniques. Auras are more of a measure of what types of techniques one can perform.

For example, if technique A requires 30% black aura and technique B requires 40% black aura, then an individual needs 70% black aura to perform both techniques simultaneously. How many times one can perform a techniques is purely dependent on their endurance.