Valkyrie, also called Walkure, is a Musicart inspired by Richard Wagner's opera "Die Walküre," embodying the archetype of a war maiden or winged goddess, often depicted as a flower blooming on the battlefield. Her personality centers on strict duty, honesty, and prioritizing missions, leading to conflicts with impulsive individuals like Jupiter; she struggles with interpersonal connections. A proud member of New York Symphonica, she wields her sword day and night to protect humanity without a bonded Conductor, following orders only from Symphonica-certified personnel. This lack of a formal partnership influences her interactions, causing her to initially address Takt disrespectfully and challenge unauthorized actions. Her demeanor softens after earning mutual respect in combat, revealing classic tsundere traits when complimented.

Valkyrie first appears confronting Takt and Destiny during an unauthorized train incident involving Black Night Siderite transport. She later collaborates with them to defend against D2 attacks, demonstrating combat prowess and fostering mutual respect. Commander Felix Schindler subsequently dismisses her from duty. She reappears assisting in the climactic New York battle against D2 swarms before being knocked unconscious by Titan during a disagreement.

Her combat abilities focus on defense and battlefield control using a sword and shield (deployable as a spinning disc). Key skills include:
- **Ride of the Walkure**: A dual passive/active granting Protection stacks after attacks (shielding rear allies) or dealing area damage scaled with defense.
- **Walkure's Healing**: A self-buff boosting physical and magical defense while granting Protection.
- **Imminent Victory**: A shield bash reducing enemy defense.
- **Divine Judgment**: A sword strike pushing enemies.
- **Heart of Valhalla**: Healing allies when Valkyrie takes physical damage.
- **Feather Protection**: Starting battles with Protection stacks.

She favors beverages like Cristatum Tea and Pomelo Dew.