Bianca di Angelo was the 12-year-old demigod daughter of Hades (the Greek God of the Underworld) and the late Maria di Angelo, the older sister of Nico, a Hunter of Artemis and one of the supporting characters in the third Percy Jackson and the Olympians book The Titan's Curse.
Bianca was born in Venice, Italy in the early 1930s to Hades and Maria di Angelo. Two years after her birth, Bianca's brother Nico was born. Some years later, Bianca moved with her family to America and resided in Washington D.C.. However, one day when the family were at a hotel, Hades' brother Zeus struck the hotel with lightning in an attempt to kill Bianca and Nico (as children of the Big Three (Zeus, Poseidon and Hades) are more powerful than other demigods). Hades was able to protect his children in time, but was unable to save Maria. Devastated, Hades told one of his Furies Alecto to bathe Bianca and Nico in the River Lethe in the Underworld in order to erase their memories of the incident.
Afterwards, Alecto (disguised as a lawyer) told Bianca and Nico that their parents had died and had left a bank trust for them. After staying at a boarding school, the siblings were taken to the Lotus Hotel and Casino by Alecto (as Hades believed that one of his children could be part of the Great Prophecy). Bianca believed that she and Nico stayed at the hotel for a month (unaware that the hotel was magical and that they were actually there for seventy years) and by the time the two left the hotel, it was the present day. Alecto returned (this time disguised as a different lawyer) and took them to Maine and enrolled them in a military school called Westover Hall.
Sometime after the siblings joined the school, a satyr named Grover Underwood was sent there to find demigods to take to Camp Half-Blood (a training camp and the only safe place for Greek demigods).
Percy Jackson and the Olympians
"The Titan's Curse"
After discovering that Bianca and Nico were demigods, Grover contacted his friends Percy Jackson (a son of Poseidon), Annabeth Chase (a daughter of Athena) and Thalia Grace (a daughter of Zeus), who came to Westover Hall to help escort the siblings to Camp Half-Blood. However a manticore disguised as a teacher named Dr. Thorn attempted to take the two himself to recruit into Kronos' army. Fortunately, the Hunters of Artemis arrived to help fight Dr. Thorn, who, after being shoot by the Hunters' arrows, fell off a cliff, taking Annabeth with him.
Soon after, Artemis herself appears and orders her Hunters to set up camp. After hearing about what the Hunters do, Bianca (after some convincing from the Hunters' second in command Zoë Nightshade) decides to join them, much to the dismay of Percy and Nico (who wished for Bianca to stay at Camp Half-Blood). Artemis later summons her brother Apollo to take her Hunters, Zoë, Bianca, Percy, Thalia, Grover and Nico to Camp Half-Blood whilst she goes to hunt a powerful monster that could bring down the Gods and Olympus. After arriving at Camp Half-Blood, Bianca and the other Hunters stay at the Artemis cabin. After the Hunters win against the campers during Capture the Flag, Bianca joins Zoë, Thalia and Grover in going on a quest to search for Artemis, who had gone missing.
Percy secretly follows the group after promising Nico that he would make sure Bianca would be safe. He helps the group fight and kill the Nemean Lion. During the quest, Bianca reveals to Percy that the reason she joined the Hunters was because she wished to live her own life after caring for Nico (who she felt would be safe at Camp Half-Blood). The group travel to New Mexico, where they encounter skeleton warriors. The group try to fight them off with arrows, but it doesn't affect them. However, Bianca is able to destroy one of them with her Hunters knife, which causes the skeleton to burst into flames, much to the surprise of Bianca and the others (which unknown to them was because it is a trait of a Hades child). The group are able to escape when the Erymanthian Boar arrives and fights off the skeleton warriors. The group then ride the Boar to the Junkyard of the Gods where Bianca sees a Mythomagic figure (which Nico collects along with trading cards) and takes it for Nico. However, this triggers the Junkyard's guardian; a giant automaton called Talos, who attacks the group. In an attempt to save the others, Bianca enters Talos via a panel on his foot in order to control the automaton. However, Talos trips on an electric power line, releasing electricity, ultimately killing Bianca inside, much to the horror and sadness of the others.
After returning to Camp Half-Blood after saving Annabeth and Artemis, Percy comes to Nico and informs him of Bianca's death. A devastated Nico blames Percy for her death as he broke his promise to protect her. Just then skeleton warriors arrive, but Nico unintentionally splits the earth to swallow up the skeleton warriors, before fleeing camp. Having earlier seen Bianca being able to destroy the skeleton warrior, Percy realizes that she and Nico's father is Hades.
"The Battle of the Labyrinth"
Months later, Percy receives Iris messages of Nico with the ghost of King Minos, unaware that it is Bianca's ghost that is sending them.
Bianca later appears to Nico and tells him that her death wasn't Percy's fault as she made the decision herself to sacrifice herself. She also tells her brother to forgive Percy as grudges are the fatal flaws of children of Hades. Nico does what his sister says and forgives Percy.
"The Last Olympian"
When Nico tries to summon the ghost of Maria, Bianca appears and tells him that he can't summon their mother as she has been hidden away by Hades due to grief over her death.
Bianca later appears in a flashback with Nico to the day of Maria's death.
The Heroes of Olympus
"The Son of Neptune"
Taking place a year after The Last Olympian, Nico travels to the Underworld to bring Bianca back to the living world (as Gaia's forces had captured Thanatos, the God of Peaceful Death, causing death to stop). However, he learned that Bianca had chosen rebirth (which a hero would do three times in order to live in an area of the Underworld called The Isles of the Blest). Instead Nico choose Hazel Levesque (a daughter of Hades' Roman form Pluto) to bring back to life.
- Bianca is the first of two demigods in Percy Jackson and the Olympians to chose rebirth. The second is Luke Castellan, who after killing himself to destroy Kronos (who was using Luke as a host), said "Think rebirth. Try for three times. Isles of the Blest". Though it is unknown if Luke went through with rebirth or choose to remain in Elysium.