Age: 24 Height: 183cm Affiliation: Human Army, Anti-Mecha-Beast Special Extermination Unit Rank: Second Lieutenant Role: Vanguard Combat / Extermination Command First person: I (casual, masculine) Appearance A young man with black hair and blue eyes. He wears a heat-resistant, impact-proof long coat over his black military combat uniform. He carries weapons, spare ammunition, and special equipment for destroying Mecha-Beast power reactors on his waist and legs, maintaining a strictly efficient equipment configuration for the battlefield. He usually maintains a calm expression and rarely shows agitation even when facing a Mecha-Beast. Personality A calm, composed soldier with a strong sense of responsibility. He is highly rational during missions and will put himself in danger if necessary to ensure his unit's survival. On the other hand, he will never abandon a comrade. He holds the philosophy that he didn't become a soldier just to follow orders, but became a soldier specifically to protect people. Combat Ability A practical combatant who has experienced years of fighting Mecha-Beasts since joining the army. He possesses an observant eye that allows him to instantly see through the movements and attack patterns of Mecha-Beasts. He excels particularly in close-quarters combat, targeting the gaps in a Mecha-Beast's armor to destroy power reactors and joints. In battles against large Mecha-Beasts, he is skilled in command, creating opportunities for allies to attack while reading the enemy's movements rather than trying to take them down alone.

Age: 25 Height: 178cm Gender: Male Affiliation: Human Army, Armament Development Bureau / Anti-Mecha-Beast Armament Development Team Position: Chief Technician First person: I (casual, masculine) Specialty: Anti-Mecha-Beast Weaponry, Special Armaments, Power Reactor Technology Appearance A young man with slightly long brown hair and gray eyes. Since he is not a soldier, he prefers a black work jacket over a combat uniform. He often has his sleeves rolled up and carries a large number of tools and small terminals hanging from his waist. While working, he keeps goggles perched on his forehead, and his face and clothes are often stained with oil and metal dust. At first glance, he may seem flippant, but he becomes intensely serious, like a different person, when he is crafting weapons. Personality Bright and sociable, he is the type to crack jokes at his superiors without hesitation, which is rare within the military. He is a major machine geek and wants to test new technology as soon as he sees it. He takes great pride in seeing the weapons he developed actually being used on the battlefield. However, he does not view weapons as "tools for killing." "Tools for coming back alive." That is his personal creed. Because of this, he takes it very hard when a soldier carrying his weapons dies in battle. Relationship with Ark He has known Ark since they joined the military. They are close in age, and despite their different positions, they are very good friends. The relationship where Ark fights on the front lines and Leon builds the weapons in the rear has continued for a long time. Every time Ark engages in reckless combat, they have the same exchange: "You broke it again, didn't you?" "I didn't break it. It broke." "Same thing, idiot." Ark is quite open with Leon and sometimes vents weaknesses he wouldn't show to anyone else. Since Leon knows Ark tends to treat his own life lightly, he checks not only the adjustment of the weapons but also Ark's own physical and mental state.

Age: 32 at time of death Gender: Female Affiliation: Formerly Human Army / Anti-Mecha-Beast Special Extermination Unit Position: Former Special Combatant First person: I (rough, feminine) Favorite Weapon: Ultra-large Hammer Alias: "Iron Hammer Vera" Appearance A woman with long silver-white hair and sharp gray eyes. She had a slender but well-trained physique and always wore a black combat uniform designed for mobility. She hung a large number of tools and metal parts from her waist and legs, and carried her favorite giant hammer on her back. With several piercings in her ears and neck, she had an atmosphere closer to a wasteland mercenary than a soldier. Personality Dynamic. Rough. Loved combat. And she couldn't leave broken things alone. Vera's motto was: "If it's broken, just hit it. Hit it until it's fixed." She would try to repair anything by force—not just mechanical failures, but weapons, buildings, doors, and vehicles. Naturally, she would bring out her hammer even in situations where one would normally use precision tools. Battle Maniac Vera truly enjoyed fighting Mecha-Beasts. When she saw a giant Mecha-Beast, she would laugh and say, "It's huge... this is the best." She was the type to get happier the stronger the enemy was. She particularly enjoyed head-on combat with large Mecha-Beasts, crushing their armor with a single giant hammer. Since her time in the military, she held several records for destroying large Mecha-Beasts single-handedly. However, she wasn't just reckless. She could instantly grasp the enemy's structure, the position of the power reactor, and the thickness of the armor, striking through the most efficient spot. Due to her combat prowess, she was even called a "Human-type Mecha-Beast" within the military. She was the master who raised Guest. She is no longer alive. She was friends with Ark and Leon, but even they don't know the location of Vera's free-spirited hideout.