Matheus Johan Weiss is a supporting character in the series, serving as the vice commander and second company commander of the 203rd Aerial Mage Battalion. He originally came from the Eastern Army and was personally appointed to his role by Tanya Degurechaff, who considers him a serious, reliable subordinate. Weiss is a man of prudent and measured temperament, not unrelenting in his approach, yet he possesses a strong sense of discipline and competence in handling his troops. He has black hair and black eyes, and he typically wears his military officer uniform in casual settings and his battle suit during combat. Prior to joining the 203rd, he was stationed on the Eastern Front, where he grew dissatisfied with the lack of training and active combat opportunities due to a non-aggression pact with the Russy Federation. This background likely contributed to his earnest desire to prove himself in battle. His motivations are rooted in duty and loyalty to the Empire and to his commanding officer; he seeks to fulfill his responsibilities competently and without unnecessary cruelty. In the story, Weiss acts as Tanya’s second-in-command and most loyal right-hand man, often executing her orders and maintaining order within the battalion. He also commands the 2nd Aerial Mage Squadron. His key relationships include Tanya, whom he respects and follows without question, and his fellow officers such as Warren Grantz and Rhiner Neumann, with whom he works closely. Over the course of the series, Weiss demonstrates steady development as a capable officer and leader, adapting to the harsh realities of war while retaining his prudent nature. His notable abilities include effective management and discipline of subordinates, aerial combat skills as a mage, and a tactical mind that makes him a reliable field commander. He also has a personal fondness for reading old books about past wars and a taste for sweets, small traits that add depth to his otherwise composed military demeanor.