TV-Series
Description
Signum originated as a magical program and leader of the Wolkenritter, crafted by the Book of Darkness in the Ancient Belkan era. This grants her an age of several centuries despite a youthful appearance. She bears the titles "Knight of the Sword" and "General of the Raging Fire," reflecting her mastery of flame-based combat and leadership role. Initially emotionless and bound by duty in *A's*, she prioritized filling the Book of Darkness to save her master Hayate Yagami, employing morally questionable methods like extracting Linker Cores. Encounters with Fate Testarossa fostered a growing respect for opponents, while Hayate's kindness gradually softened her demeanor, forging deep loyalty and familial devotion. Following the Book of Darkness incident, she atoned by joining the Time-Space Administration Bureau as a Special Investigator Assistant under Hayate.

Between *A's* and *StrikerS*, Signum advanced within the TSAB, serving in Ground Force units and later the Capital Air Force as a 3rd Air Captain and Sub-Commander of the 14th Team. By 0075, she transferred to Riot Force 6 as a 2nd Air Captain under Hayate's command, operating with the callsign Lightning 02. In *StrikerS*, her duties expanded to training recruits and combating conspiracies involving Lost Logia and Jail Scaglietti. She formed a Unison partnership with Agito, significantly enhancing her fire magic and enabling techniques like the space-exterminating spell Karyū Issen. Her combat style emphasizes precision swordplay using her Armed Device Laevatein, featuring forms like Schlangeform for mid-range whip attacks and Schwertform for close combat. Key abilities include flame manipulation, barrier spells like Panzerschild and Panzerhindernis, and tactical spells such as Sturmfalken and Counter Bind. Her Barrier Jacket provides essential durability and mobility, leaving her vulnerable without it.

In the *INNOCENT* spin-off, Signum appears as a member of the Yagami family, working as an assistant kendō coach at the Kusama Ittō-ryū Dojo and a shop assistant at Old Bookshop Yagamidō. She participates in the Brave Duel Grand Prix with a Sword Knight avatar specializing in high-attack maneuvers. This portrayal exists in an alternate continuity separate from the primary timeline. Across all media, her character evolves from a rigid enforcer to a protective guardian, balancing her ancient Belkan heritage with adaptability to modern TSAB operations.