Aura, also known as Aura the Guillotine, is a major antagonist and a member of the Seven Sages of Destruction, a group of powerful demons who served directly under the Demon King. She is a petite female demon with long pink hair that is tied into two large pigtails, each further divided into three smaller braids. Her appearance includes dark blue eyes, two light brown horns, and an outfit consisting of a dark blue sleeveless bodice with a cutout at the navel, a white ruffled skirt, a large pink frilly cape, and striped leggings.

As a demon, Aura lacks human emotions such as empathy or compassion. She is characterized as selfish, power-hungry, and individualistic, harboring no sense of loyalty toward her own subordinates. When she learns of the deaths of her servants Lügner, Linie, and Draht, she shows no distress whatsoever. Her only apparent loyalty was toward the Demon King himself. Despite her arrogance and confidence in her magical abilities, Aura is also notably cautious. When facing enemies she cannot defeat, such as the Hero Party, she chooses to retreat rather than sacrifice herself, a tendency that allowed her to survive the Demon King's downfall. She enjoys battles where she believes she has the upper hand and maintains strong faith in the superiority of her magic.

Aura served the Demon King for over five hundred years as one of the Seven Sages of Destruction. She built an army from victims subjugated by her magic and earned her fearsome title Aura the Guillotine by beheading anyone who showed resistance to her control. She faced the Hero Party in battle, suffered the loss of a significant portion of her undead army, was injured by Himmel, and was forced to retreat. Following the Demon King's defeat, Aura remained hidden for approximately fifty years until Himmel's death. After Himmel passed away, she reappeared and waged war to take over Graf Granat's Domain in the Northern Lands, a conflict that resulted in the death of Graf Granat's son.

In the story, Aura serves as the main antagonist of the Aura the Guillotine Arc. She sends her three executioners, Lügner, Linie, and Draht, as messengers to negotiate peace with Graf Granat, but her true intention is to deceive him into disabling the barrier protecting the town, giving her army free access. She commands an undead army of decapitated soldiers who remain under her control. Her key subordinates are her executioners, though she holds no genuine care for them. Her primary adversary is Frieren, an elf mage she underestimates fatally.

Aura's defining ability is her unique magic called the Spell of Obedience, or Auserlese, which manifests as a pair of scales. Using these scales, she weighs her own soul against her target's soul. If her mana is greater than her opponent's, she gains permanent control over their body. However, this spell carries immense risk because if the opponent possesses more mana, Aura herself becomes permanently enslaved to them. The scales are objective and provide Aura no inherent advantage in the measurement. While a person with sufficiently strong willpower can temporarily resist the control, Aura circumvented this problem by simply beheading those she subjugated.

Aura's development culminates in her confrontation with Frieren. Confident in her five hundred years of mana accumulation, she uses her Scales of Obedience against Frieren. However, Frieren reveals that she has spent over a thousand years concealing her true mana levels, a strategy demons cannot comprehend because they view mana as a measure of status and identity. When Frieren releases her full mana, it completely dwarfs Aura's, causing the scales to tip in Frieren's favor. Now under Frieren's control, Aura is forced to obey the command to kill herself, decapitating herself with her own sword in a moment of frustration and humiliation. Her defeat serves as a demonstration of how Frieren's lifelong discipline and deception overcome raw power and arrogance.