TV-Series
Description
Ellen Mira Mathers is a prominent character first introduced in the fifth volume of the light novel series, making her animated debut in the first episode of Date A Live II. She serves as the secretary and right-hand to Isaac Ray Pelham Westcott, one of the founders of the Deus Ex Machina Industry, or DEM. Within this organization, she holds the position of Director of the Second Executive Department. Known by the call sign Adeptus 1 and the epithet "The World's Strongest Wizard," a title she claims with great pride, she is also referred to as the "Eternal Mathers." She is one of the last four remaining pure-blooded magicians and her actions were pivotal in the creation of the first Spirit, an event which also caused the catastrophic Eurasia spacequake.

In terms of background, Ellen hails from a hidden community of magicians. Her early life was marked by tragedy when ordinary humans, fearing their magical abilities, burned the village to the ground. Alongside Westcott, her friend Elliot Woodman, and her younger twin sister Karen Nora Mathers, she witnessed the destruction. This traumatic event shaped her worldview and led her to support Westcott's ambition to create a new world. Decades ago, she assisted Westcott and Woodman in using a sorcery called the Spirit Formula, which successfully gathered all the world's mana into one location. This act created the first Spirit and the parallel dimension from which others would emerge, but also triggered the first catastrophic spacequake. At some point after this, Woodman left DEM to form the organization Ratatoskr, an act Ellen perceived as an unforgivable betrayal, a slight she has never forgotten.

Ellen's personality is complex, defined largely by a stark contrast between her professional composure and her hidden traits. On the surface, she is calm, analytic, and ruthlessly efficient in carrying out her duties, acting as Westcott's primary instrument of force. She is exceptionally loyal to him and will remove any obstacle to his goals without hesitation. In battle, this cold demeanor often gives way to a battle-hungry and bloodthirsty nature; she takes great pleasure in testing her strength against powerful opponents and has been known to look down on those she deems weak. However, outside of her combat gear, her personality presents a sharp contrast. Without her CR-Unit, a piece of powered armor called Pendragon, her physical abilities are no better than, or even worse than, an average person. She has a documented fifty-meter run time of 21.5 seconds and requires a flotation board to swim. This has led to her being easily overwhelmed by mundane situations, such as being ambushed and detained by a group of ordinary high school girls, much to her humiliation. Despite her fearsome reputation, she also exhibits traits of a typical young woman; she can be easily embarrassed, is fiercely prideful about her status, and has a peculiar habit of twisting everyday situations to fit her personal narrative of "strength," such as only stepping on the white stripes of a crosswalk because they symbolize victory.

Her primary motivation is twofold: serving as the sword of Isaac Westcott to realize his vision, and a deep-seated personal grudge against Elliot Woodman, whom she may have romantic feelings for. Her loyalty to Westcott is absolute, and she vows never to lose a fight for his sake. Her hatred for Woodman stems from his perceived betrayal when he left DEM, but also from a more personal pain. She and her sister Karen both had feelings for Woodman, and when he left, he took Karen with him, leaving Ellen behind—a wound that fuels her anger and desire for revenge.

Ellen's role in the story is that of a formidable antagonist and a direct agent of DEM's schemes. In Date A Live II, she is dispatched to observe the Spirit Tohka Yatogami during a school trip. In this mission, she disguises herself as a photographer but is constantly foiled by the antics of three ordinary students, a source of great frustration for her. She later engages Tohka in direct combat to verify her identity as the Spirit "Princess" who had disappeared three months prior. During this encounter, she easily defeats a limited-release Tohka, demonstrating her overwhelming power. Her role continues to expand as she leads operations to capture and interrogate Spirits, such as Nia Honjo and Natsumi, subjecting them to brutal methods in an attempt to force them into their inverse forms.

Her key relationships define much of her character. Her relationship with Isaac Westcott is one of total, fanatical loyalty, with internal DEM rumors even suggesting she is his mistress. She is his most trusted operative and closest confidant. In stark contrast, she harbors a powerful hatred for Elliot Woodman, the founder of Ratatoskr, viewing him as a traitor to their shared past and goals. This is further complicated by her unresolved romantic feelings for him. Her relationship with her sister, Karen Nora Mathers, is estranged, as Karen sided with Woodman and joined Ratatoskr. She also has a noted rivalry with the young wizard Origami Tobiichi, who is only the second person in Ellen's life to ever inflict an injury on her in combat.

Ellen undergoes notable development. After the death of Westcott in the final arc of the story, her memories involving him and the DEM are permanently and completely erased. Freed from the trauma and obsession that defined her, her personality becomes much more meek, shy, and easily flustered. She loses her bloodthirsty and arrogant demeanor and ultimately becomes a physics teacher at Raizen High School, living a peaceful and normal life.

As for her abilities, Ellen is considered the most powerful wizard in the world when utilizing a CR-Unit. Her signature unit is the white-and-gold Pendragon. With it, she can generate a Territory, a defensive and augmentative field, with a precision and magnitude that surpasses any other human. Her preferred weapon is a large laser blade called Caledfwlch. Her physical speed and strength, augmented by her unit, are sufficient to easily overwhelm most sealed Spirits and fight on equal terms with an inverse Spirit, even while wounded. A testament to her skill, she is one of the few wizards capable of manifesting and maintaining a powerful Territory without wearing her full CR-Unit, though this requires intense concentration. However, her most critical weakness is that without her CR-Unit's realizer to augment her, her pure physical athletic ability is far below average. This discrepancy between her power in combat and her mundane fragility is one of her most defining characteristics.