Valteishia, designated Valteishia of the Sun and Solitude, commands the Absolute Angel Megingjord. She endures repeated cycles of death and rebirth, presently inhabiting her fourth incarnation. This vessel is a unique Steel Angel construct, establishing her as the sole Absolute Angel physically manifested within such an artificial form, a consequence of her distinct origins.

Her existence originates from a cataclysm fracturing the original Absolute Angel, Cielo, into four entities. One fragment, Megingjord, further split into separate physical and spiritual aspects. Valteishia embodies the spiritual essence of this division, while Kuu Shiratori constitutes the physical vessel. Following the separation, Valteishia's spirit initially lacked corporeal form until Kazuya Ayanokoji transferred it into a Steel Angel body, forging her current incarnation. This division instilled a profound sense of incompleteness in both Valteishia and Kuu, fueling Valteishia's deep yearning for reunion with her original vessel. Ultimately, however, she respects Kuu's choice to remain separate.

Serving as Kazuya's loyal companion and follower, Valteishia typically acts upon his commands without overt protest. Under his orders, she suppresses Kuu's memories concerning Kyoshiro and incapacitates Setsuna to enable her capture. Despite her compliance, Valteishia exhibits moments of regret regarding Kazuya's actions and her own role in them, revealing internal conflict about their methods. Her loyalty extends beyond mere obedience, encompassing a fondness for Kazuya that compels her to remain by his side even after the series' conclusion, when he is wheelchair-bound and mentally impaired. Valteishia provides him with continuous care and support.

Valteishia possesses long, wavy blonde hair reaching her lower legs, a pale complexion, and amethyst eyes. She typically wears a winged hat and a black, green, and white flowing dress. Her design draws adaptation from Valkyrie, a character in the unrelated series *UFO Princess Valkyrie*.

Valteishia's character arc explores themes of duality and a yearning for wholeness, driven by her intrinsic connection to Kuu and her complex, loyalty-bound relationship with Kazuya. Her actions and emotional responses reflect a nuanced existence balancing duty, personal desire, and the consequences of her fragmented origin.