Asteria Lizamarie de Roschefall is the granddaughter of the chairman of Novumundus, an organization focused on studying the Rin-ne phenomenon. She wields significant authority from the Pharos facility, overseeing Vox Unit operations. Her appearance features Lolita-style fashion and a memoria mark on her chest, mirroring the main Vox pilots.

Acting on historical records showing the Vox Aura (Midori) nearly destroyed the world 20,000 years ago, Asteria banned Madoka Kyouno from piloting it. She fears its activation could trigger the Rin-ne, risking a repeat of that ancient catastrophe. This decision reflects her deep-seated responsibility; Asteria is the reincarnation of Queen Maycun, the figure from 20,000 years ago whose actions almost destroyed Earth by "opening" the Rin-ne. This connection explains her memoria mark and drives Novumundus's mission to prevent the Rin-ne's return.

Asteria leads with a businesslike and authoritative style, prioritizing duty and strategic goals, such as refusing Villagulio's demands for the Vox Units. Though generally composed and calm in conflict, emphasizing protocols and historical precedents, she occasionally displays moments of levity like minor physical interactions. She exhibits maturity beyond her years, principled decision-making, and a strong sense of responsibility to prevent disaster. Her interactions show respect for others' perspectives, evident in discussions with Yoko Nakaizumi about the Vox Units before the piloting ban.

Throughout events, Asteria evolves from a detached authority figure to someone directly confronting her past identity as Queen Maycun and its implications for stabilizing the Rin-ne in the present. Her actions consistently align with Novumundus's mission to safeguard Earth and maintain neutrality amid interplanetary tensions.