Sylvie Lumiere

Sylvie Lumiere (シルヴィ・リュミエール, Shiruvi Ryumiēru) was a passenger aboard the Advena Avis. She was romantically involved with Gretto Avaro.

Abilities
Sylvie possesses absolute immortality, unable to die, age, get sick, or be permanently wounded.

Both anime and novels
Sylvie, about 17 years old, is among the alchemists on board the Advena Avis. She is present when Maiza Avaro summons a demon, and receives a cup of the Elixir of Life. However, she stores her Elixir in a vial rather than drinking it immediately. Later, during Szilard Quates's murder spree, she is seen looking for Gretto so that they can hide together. Szilard, meanwhile, eats Gretto and inherits his romantic attraction to Sylvie, which Szilard's warped mind expresses as a desire to eat her. He corners her in one of the ship's passageways and attempts to do so, but as she is not immortal, the attempt fails. Nile then arrives and attacks Szilard, driving him above decks, where he is eventually knocked overboard. Sylvie is heartbroken at the news of Gretto's death; Elmer C. Albatross attempts to comfort her, but his cheerful attitude proves unhelpful in the face of grief. When Sylvie is in her early twenties, she drinks her portion of the Elixir. In the 1930s, she is a professional singer.

Novels only
Sylvie states that her interest in alchemy was inspired by an admittedly vain desire to achieve "eternal beauty", a concept she had been exposed to in fairy tales as a child. She confessed this dream to Gretto, who told her that her appearance was not the most important thing about her in his eyes. He subsequently asked her to marry him and live with him for eternity if they should become immortal, and she accepted. Her determination to obtain eternal beauty only increased, so that Gretto would be married to the most perfect woman possible. After his death in 1711, she attempted suicide, but Maiza and Elmer stopped her. After this incident she no longer grieved openly, but Denkuro, a fellow passenger, noted that there was rage in her eyes, evidence of her desire to avenge Gretto's death. As they were disembarking in Boston, Sylvie told Denkuro that if her life was going to be dominated by grief and vengeance, then she no longer wished to live forever. Nonetheless, she drank the Elixir when she was fully grown. She casually tells people that this was so that she could preserve the height of her beauty, as she had originally intended to do, but she later confesses that her true reason for waiting was so that she could track down and eat Szilard without being recognized by him. By 2001, she is traveling with Maiza Avaro and Czeslaw Meyer in search of the surviving immortals, and is with them when they arrive in Elmer's European village. In 2002 she reunites with the surviving immortals aboard the cruise ship Exit.

Anime only
Sylvie is in New York in 1932 and learns of Szilard's death at Firo's hands, although it is not certain how she found out. She visits Alveare, observes Firo playing dominoes with the other Martillo Family executives, and leaves before Maiza can recognize her. Outside, she meets Elmer and explains to him that she had been planning to "become one with Gretto" (the context does not make it obvious whether she meant that she wanted to eat Firo, or was going to ask Firo to eat her) but that she saw something in Firo that reminded her of Gretto, which dissuaded her from her intention.