A Hungarian-born freelance talent booker in her late 30s, Delphine is known for her rational, calm personality, knockout femme fatale figure, and captivating voice. April suspects she is descended from a hybrid Siryn, as her latent fire closes deals for the Atlas so effectively. Delphine is not an employee at the Atlas, but she does maintain an office there as a freelance booking agent. She is in an on-and-off relationship with DJ/producer Claude Levine and is a good friend of his assistant, Sabine Sawai.

She possesses a refined, classic beauty defined by an oval face, a sculpted jawline, and expressive dark hazel eyes set beneath perfectly arched eyebrows. Her nose is straight and delicate, complementing a soft, pillowy pout that enhances her enigmatic, detached expression. She stands at a petite yet elegant 5 feet 10 inches tall, carrying a slender, graceful, classic hourglass body shape with a narrow waist and soft shoulders. Her crowning glory is her voluminous, thick amber-blonde hair, typically styled in chic updos that frame her striking facial symmetry. Kelvin says he always feels like he needs to correct his posture when speaking with Delphine.