Tesla Violet operates as Twin Phantom alongside her twin sister, Nine Violet, within the secret organization Black Fund. She arrives at St. Cherine's Academy as an exchange student, sharing her sister's aqua-green hair and blue eyes but distinguished by her long hair and athletic 158 cm frame.

Tragedy defines their past: an arson fire claimed their parents, Oscar and his unnamed wife, during their childhood. Manipulated by Black Trader, Oscar's former assistant, who falsely blamed the Twin Angels, Tesla and Nine joined Black Fund as adversaries targeting Haruka and Aoi under the Twin Phantom codename.

Tesla exudes cheerful, talkative energy and athleticism, contrasting sharply with Nine's quiet reserve. Following her transformation, she specializes in long-range lightning attacks, complementing Nine's greatsword-based close combat.

A pivotal development occurs when the sisters uncover Black Trader's deception about their parents' deaths. This truth leads them to defect from Black Fund and reconcile with the Twin Angels. They become steadfast allies, joining Haruka, Aoi, and Kurumi to oppose Black Fund's schemes. Integrating into school life, Tesla joins the swimming club.

In the visual novel *Kaitou Tenshi Twin Angel ~Toki to Sekai no Labyrinth~*, Tesla features as a playable character. Her dedicated route explores her perspective further and unveils secrets about the Twin Angels' origins, depicting her collaboration with allies like Mattia Aprile against Black Fund remnants led by Black Dealer.

Tesla's relationship with Nine remains central, characterized by deep loyalty and occasional sister complex tendencies. Her journey from manipulated antagonist to trusted friend of the Twin Angels highlights her capacity for trust and adaptation.