Tesla Violet, one of the Twin Phantoms serving the secret organization Black Fund, operates alongside her younger sister, Nine Violet. She wields long-range, electricity-based attacks and possesses long aqua-colored hair. After their parents died in an arson attack, Black Trader rescued and adopted the sisters, deceiving them into believing the Twin Angels caused their parents' deaths. This lie fueled Tesla and Nine's initial antagonism towards Haruka and Aoi.

Nine developed a close relationship with Haruka Minazuki before learning she was Red Angel. Discovering Black Trader's manipulation regarding their parents' fate and his true malicious intent, Tesla and Nine severed ties with him. They reconciled with the Twin Angels and became allies. Following this shift, Tesla continued collaborating with the group to protect the Seven Amulets from those seeking to misuse their power.