TV-Series
Description
Adeltrud Alter, who is almost exclusively called Adi, is a central figure in the story of Knight's & Magic. She is the twin sister of Archid Alter and the daughter of Joachim Serrati, making her the half-sister of Stefania Serrati. As an illegitimate child, she and her brother were not recognized as nobility, though they still grew up in relatively comfortable circumstances. Her first encounter with the protagonist, Ernesti Echevarria, occurred when she fell from a roof and he saved her, an event that immediately sparked her intense fascination with him.

In terms of personality, Adi is characterized as cheerful and active, with a notable fondness for cute things. This fondness is directed most intensely at Ernesti, whom she adores and hugs frequently. Her childhood behavior was somewhat rambunctious and bossy, but she matures into a more composed young woman, though her core personality remains direct and affectionate. A key aspect of her personality is her complete devotion to Ernesti, to the point where she does not view him as a potential romantic interest but as the sole object of her considerable affection. This manifests as a desire to be near him constantly, including in situations that others might find improper, such as bathing with him.

Adi's primary motivation is to remain at Ernesti's side, both personally and professionally. She first asked to learn to pilot a Silhouette Knight simply because Ernesti was interested in them, a decision that led to her becoming a skilled Knight Runner. Her role in the story is defined by her position as Ernesti's exclusive adjutant within the Silver Phoenix Knights, a unit she joins alongside her brother. She is not merely an assistant; she is one of the unit's top pilots, acting as a test pilot for new models and a drill instructor for other squad members. Her skills are considered to be on par with her twin brother's, placing them both at the elite level of the order.

Her key relationships are tightly interwoven. With her twin brother Archid, she shares a deep bond as siblings and comrades, often working in tandem. Her relationship with her half-sister, Stefania, is more complex; while she seems to like her, she is initially unsure how to act around her legitimate sibling. However, her most defining relationship is with Ernesti. She begins as his friend and pupil, learning the fundamentals of magic from him. This relationship eventually deepens, and in the source material, she formally becomes his wife after being the one to propose to him. Her devotion to him only intensifies after marriage, leading to displays of jealousy and an adamant refusal to be separated from him, even on the battlefield.

Adi undergoes significant development from a young girl infatuated with her savior to a confident warrior and, ultimately, a wife. A pivotal moment of foreshadowing occurs when she experiences a precognitive dream of her own wedding to Ernesti. Her development is also marked by her increasing maturity and agency, culminating in her direct proposal to Ernesti, declaring that she will always fight by his side and will follow him even if he tries to leave her behind.

Regarding notable abilities, Adi is an exceptionally talented Silhouette Knight pilot. Her fighting style is described as "precision first," which complements her brother's power-focused approach. As a direct disciple of Ernesti, she has mastered the demanding "sense of full control" required to pilot his highly advanced and sensitive machines. Her true genius, however, lies in aerial combat, where she demonstrates an almost invincible level of skill. In one instance, she single-handedly evaded and "defeated" an entire ten-pilot squadron in a mock battle without taking a single hit, a feat that highlights her prodigious talent. Her ability to adapt to the unique handling of Ernesti's custom mecha is unmatched, and she is one of the few pilots capable of operating the combination unit, Magatsu Ikaruga, in sync with him. She is also a sensory learner, which makes her a difficult instructor, as she teaches by feel and instinct rather than by theory, using abstract terms like "swish, twist, and flick" to explain complex maneuvers.