Aura is one of the two balancing forces in the universe, along with mana.
Mana and aura balance each other out. Mana provides life and nourishes it, while aura is more caustic. Without aura, there would be too much mana and life would become bloated. Aura keeps life in check, like a predator to prey.
Too much aura, however, is equally detrimental to life. In a low mana environment, aura is more prone to igniting. When ignited, aura repels mana and acts like a corrosive flame. It can tear apart magic and mana. Extreme bouts of aura can even chip away at life.
Although potentially harmful to life, all living thing have aura of varying degrees and quality and is linked to the emotional character of a being. An extreme and sudden outburst can cause aura to ignite into a dangerous fire. A trained aura user, however, can ignite and tame their aura through practice, self-discipline, and emotional control. Such aura users can use their aura as a weapon, using the fiery-force to tear apart magic and mana.