This question was asked by L.Marie.
I mention auras and magic a lot in my books and blog. They are the core of magic in Windemere and I spoke about their origin in a post from long ago. The basics are that the plane of magic (Mylrix) crashed into the physical plane, which merged the auras with their real world owners. Doing so means there is a higher chance of people becoming casters and demonstrating unique powers. For example, Luke’s sound sight and Sari’s immovability exist because of this event. These powers still could have appeared, but they would not be as potent if they did emerge.
Still the question is how the auras influence magic. Well, they are the source. A person utilizes their aura or the aura of someone else to create a spell. This means that when Nyx hurls a fireball, she’s transforming her aura into flames and throwing them. It also means that when the Lich hits with a decaying spell, he is using someone’s aura against them. It brings a bigger sense of violation to necromancy, which revolves around altering the energy of someone else instead of your own.
Now this doesn’t mean everyone can become a caster. You still need a certain amount and potency of aura as well as the ability to control it. For example, Luke has the power without the ability to turn it into spells. Such an aura can develop unique abilities for a person, but there typically needs to be a trigger. So, casters are not around every corner even though they are common. This is why you don’t see a lot of ‘oohs’ and ‘aahs’ when Nyx or Sari cast magic. People maybe find it pretty and the level of power on display is impressive, but the overall awe isn’t much. Unless you’re at the wrong end of the spell, but that’s more fear than awe.
That’s the overview of auras since there are a lot of nuances. Here are a few more pointers:
- Most undead do not have auras. Ghosts are composed entirely of aura and Dawn Fang vampires (new worlds) are not really dead. All other undead species come up as voids when a caster is using magic sight.
- Mental and physical trauma can cause an aura to go dormant.
- Certain levels of spells opens the caster to getting phantom effects or connecting with the targets. For example, Nyx casting the genocide spell caused her to feel the death of every goblin that she struck. This leads to aura-harming trauma.
- There are some special caster types as listed in the linked post above. Each one does something different with aura. (The truth about Nyx is not on that list.)
- Priests use a combination of their own aura and the ‘donated’ aura of their deity after praying. Sometimes they can get a mid-action boost from their deity.
- Magic items have their own auras, which synch with the user’s aura. This is why you don’t have to be a caster to use most of these items. Some still require activation words, rituals, and motions. Also, just because you can activate the deflector axe doesn’t mean you’ll know how to use it as a weapon.