Nacht is a Lost-Type Magical Heritage, a category of sentient magical weapons, whose physical form is the legendary blade Dáinsleif. Unlike a simple tool, Nacht possesses a distinct female personality and consciousness. She can manifest a human form, a state she prefers over being kept sheathed in anti-magic material. Nacht is wielded by Haunted, a necromancer and alchemist, and serves as his primary weapon and close companion. Her personality is characterized by a sharp, bickering dynamic with Haunted, often criticizing his hobbies and questionable impulses, yet she is deeply devoted to him, affectionately clinging to him and stating that there is no one else for her. In the story, Nacht appears as a supporting figure aligned with Haunted’s faction, Valhalla. Her role primarily involves being a powerful magical armament in Haunted’s hands, but her sentience and human form also allow her to interact independently. As a magical heritage, her abilities likely stem from the properties of Dáinsleif, a blade with legendary significance, though specific combat capabilities are not detailed in the available material. Her development is limited but shows a preference for autonomy in her human form and a deepening bond with Haunted.