Aura

"Well Flow isn't it's official name is it?"

Aura is the gas that was contained within Origin and brought to earth during the 1st Calamity.

Physical Properties

 * Diluted Ethraksha.
 * Becomes intangible beyond a certain level of pressure. Meaning that there is no way of manufacturing Ethraksha.
 * Behaves like thick smoke.
 * Completely colorless.

Life's dependence on Aura
Aura used to be incredibly poisonous, but thanks to the events of the 1.5th Calamity, L.U.C.Y used her newly created Tomahtra to enact the Divine Blessing. Nowadays people intake Aura, compress it into super tiny amounts of Ethraksha and sustain themselves off of the energy from the miniature explosions that occur when the stuff makes contact with organic matter.

Aura is present in the air and in living organisms. If it's alive, it needs Aura to stay alive. There's a much higher concentration of it in living things than there is in the air. Most living organisms contain 95% of the amount of Aura required for it spontaneously concentrate into Ethraksha.

Aura is contained in the most liquidous part of a living thing. For animals, that'd be their blood or Haemolymph. Plants store it equally throughout their entire body. Animals breathe the stuff in, and plants suck it in through...the soil, I guess? Maybe through the air too.

The less Aura something has, the more Aura their body absorbs when it breathes in.

Aura Deprivation
If a person's Aura levels fall below a certain level, they will begin to suffer from Flow Deprivation. They will experience shortness of breath among 'other symptoms that vary depending on the Magic System the person was born with. 'The severity of these symptoms increase the more Aura a person has lost.

Aura Deprivation becomes lethal when inflicted for longer than a certain amount of time, this also varies depending on the Magic System:

There are three efficient ways to recover from Aura Deprivation:
 * 1) Aura-Rich foods. Pomegranates, Mangoes, and Animals that can use powerful Magic are some examples.
 * 2) Being near restorative Ethr Crystals. Most big hospitals have one of these.
 * 3) Taking faster, deeper, breaths. Since the body absorbs Aura through lungs, just like it does oxygen, breathing faster will help you recover more.

Verlode (Aura Overload)
If a person ends up with more Aura in their body than they can handle they'll begin to suffer from an Aura Overload, colloquially known as being "Verloded".

Symptoms vary from Magic System to Magic System, but it's just as deadly regardless of what abilities a person has. Organisms that do not have a Magic System won't have symptoms beyond the ones detailed below.

Once the Aura concentration goes beyond a certain point, it will reach begin to condense into Ethraksha from within the body, and once that happens you are either ' dead or damaged beyond repair. '

Upon making contact with organic matter, the mass of Ethraksha will explode. This would severely damage whoever gets hit. Any Ethraksha that hasn't evaporated back into Flow will begin to assimilate the information surrounding it into itself, that info being the person's body in this case. Depending on the volume of foreign Ethraksha that has entered the body, the results of this stage range from immensely painful to guaranteed death.

Ethraksha rarely ever absorbs organic information completely, so if a Verlode reaction was triggered by a volume of Ethraksha large enough to absorb the entire body, it would most likely result in an Eidolon being created from the victim's corpse.

This would not happen when being Verloded with a small volume of Ethraksha that cannot spread throughout the entire body: the Programming Stale effect would prevent the Ethraksha within the ml range from absorbing more than a torso's worth of organic information.

A fate worse than death, Verloding someone is A CRIME PUNISHABLE BY DEATH IN ALL NINE REGIONS

Breath control
It's been important since before I even knew what Demon Slayer was. Breathing too fast for too long will increase the amount of Ethraksha in your body above safe levels and promptly kill you from Aura Overload. Not breathing for too long will decrease the amount of Ethraksha in your body below safe levels and kill you from Aura Deprivation.

Trivia
Aura used to be called Flow, but ever since I came up with the Idea that there will be more than one Magic System, I had to change the name to something more universal. Each Magic System has it's own contextual name for Aura.