at Camp Jupiter. After Python's power blocks the Oracles, Ella's knowledge of the Sibylline books becomes vital. In The Tyrant's Tomb, Ella is shown to be in a relationship with Tyson and is transcribing the books by tattooing information onto Tyson's skin. Ella helps Apollo against Triumvirate Holdings with her prophecies and provides Apollo with the first part of a prophecy that he has to seek out the rest of in The Tower of Nero. Ocypete – A Harpy whose name means "swift wing". She is a member of Camp Half-Blood's "Cleaning Harpies". Hunters of Artemis – A group of girls who gave up love in exchange for immortality and youthfulness. As their name implies, they are followers of Artemis in her hunts, though a lieutenant is chosen to lead them when Artemis is not around. Members are recruited both from mortals and demigods. They have a strong aversion to males and tend to regard them as disgusting and untrustworthy. However, their immortality will fade if they ever fall in love or "fall in battle". In battles, the hunters primarily use bows and arrows to attack. Zoë Nightshade serves as the group's lieutenant for over 2000 years, but after her death in The Titan's Curse, she is succeeded by Thalia Grace. In The Blood of Olympus, many members are massacred by the Gigante Orion (who is not the mythical Orion that Artemis knew) while attempting to give Reyna time to escape from Puerto Rico. In The Tyrant's Tomb, Reyna joins the Hunters. Bianca – A twelve-year-old daughter of Hades and the older sister of Nico. Percy, Annabeth, Grover, and Thalia rescue her and Nico along with the help of the Hunters of Artemis from Westover Hall and the manticore Dr. Thorn. In The Titan's Curse, she attempts to save Artemis, alongside Percy Jackson, Grover Underwood, Thalia Grace, and Zoë Nightshade. She sacrifices herself to save the group from a mechanical prototype of Talos. For a while, this causes Nico to be mad at Percy but Nico has a secret crush on Percy which is mentioned in The House of Hades when Jason and Nico meet Cupid. Nico tries to summon Bianca from the dead many times but only meets her when Percy comes. In The Battle of the Labyrinth, Bianca (as a spirit), and later in The Son of Neptune, she tries for rebirth on the Isle of the Blest.