Amuria is a significant supporting character whose presence looms large over the narrative of Simoun, despite her limited on-screen appearance. She is introduced as the original sagitta, or rear-seat pilot, to Neviril, the regina and leader of the elite flying squadron known as Chor Tempest. Before the events of the story, Amuria and Neviril formed an inseparable pair, both as piloting partners and as romantic companions, a bond that was forged almost immediately upon Neviril joining the corps.

In terms of personality, Amuria is portrayed as a remarkably determined and forward-driven sibylla. Unlike some of her peers who focus on the priestly and ritualistic aspects of piloting the sacred Simoun, she possesses a keen interest in the aircraft as instruments of power and a means to achieve greater heights. Her determination is intertwined with her relationship; she is frequently seen calming Neviril during moments of stress, reassuring her partner that the challenges they face, including taking the Simoun into battle, are inevitable. Her motivations are deeply rooted in her love for Neviril and her ambition to push the boundaries of their abilities together. This drive is most clearly expressed in her insistence on performing the Emerald Ri Maajon, an extremely powerful, forbidden, and difficult aerial maneuver.

Amuria's role in the story is that of a catalyst. She is lost during Chor Tempest's first combat action against the nation of Argentum when she and Neviril attempt the Emerald Ri Maajon. It was Amuria's idea to try the maneuver, and her disappearance during the attempt is the inciting incident that shapes the emotional arc of the series, particularly for Neviril. Her death leaves a profound void, plunging Neviril into a state of grief and trauma that defines her character for a significant portion of the story. The mystery surrounding the exact nature of her disappearance, as a body is never found, becomes a point of lingering ambiguity.

Key relationships are central to understanding Amuria. Her bond with Neviril is the most critical, described as one of immediate connection that evolved into a romantic and physical relationship. Their dynamic was one of mutual support and ambition, with Amuria often taking the role of the instigator, pushing them both toward new challenges. Her devotion is demonstrated through intimate gestures, such as kissing Neviril to calm her or to make a vow before battle, reaffirming that their love was the core of their partnership as sibyllae. The shadow of this relationship is cast directly onto the main character, Aaeru, whose resemblance to Amuria in spirit and determination is noted by others, and who eventually becomes Neviril's new partner.

Regarding development, Amuria's personal journey is cut short by her sacrifice. Her primary narrative function is to undergo a pivotal moment of change: the attempt of the Emerald Ri Maajon. This act, intended to strengthen her bond with Neviril and overcome their enemies, results in her physical disappearance from their world, an act that transforms her from a living character into an idealized and haunting memory for the rest of the cast. As a sibylla, her notable abilities are implied to be exceptional, as she and Neviril were regarded as one of the best duos in existence. Her primary demonstrated skill is her piloting ability, particularly her determination to master the complex and dangerous Emerald Ri Maajon, a feat that speaks to her technical ambition and skill.