She Had A Fling With Voldemort
Although many fans speculated that Bellatrix and Lord Voldemort's relationship was more than what was explored on screen or in the book, it was never outright proven in the original series. Her relationship was later confirmed with Harry Potter and the Cursed Child.
Delphi, like Voldemort himself, was conceived under a love potion. Bellatrix was desperately in love with Voldemort and wanted badly to bear his child, so she spiked his drink with a love potion so that he would sleep with her.
Bellatrix, herself a case study in the Dark Tetrad personality traits (narcissism, Machiavellianism, psychopathy and sadism), is drawn to those traits in Voldemort. She sees Voldemort as the only person worthy of her devotion. He is the only one who surpasses her in power, cruelty and ruthlessness.
Yes, Bellatrix and Voldemort did have a child.
It's revealed in the stage play Harry Potter and the Cursed Child that before Voldemort died, he and Bellatrix were… intimate… which led to them having a baby girl which they named Delphini Riddle.
As Bellatrix and Voldemort were both killed in the Battle and Bellatrix's husband Rodolphus was imprisoned at Azkaban, Delphi was raised by Euphemia Rowle, a Death Eater. However, the life at Euphemia's was miserable for Delphi as Rowle did not really care for her and only took her in because she was paid for it.
Harry Potter and the Deathly Hallows
In this book, Rowling reveals that Bellatrix is the guardian of Helga Hufflepuff's cup (though she is unaware that it is a Horcrux), which Voldemort has entrusted the Lestranges to keep in their Gringotts vault.
His reaction to Bella's death was akin to his reaction at the loss of the Cup, which was when he realised that his own immortality was jeopardised amidst war and his own death could have been near.
Draco had several reasons for lying to Bellatrix, including the fact that he was never a bad person. Moreover, he no longer found working for the Dark Lord appealing and hated how Voldemort treated his family. He did not intend to harm anyone and believed Harry was the only person capable of defeating Voldemort.
Bellatrix Lestrange Killed her own cousin, Sirius Black: She killed Sirius (who was her cousin) during the battle at the Department of Mysteries. She was remorseless and was cackling in glee after she had murdered Sirius.
Why doesn t Harry use Avada Kedavra on Bellatrix? Harry didn't use that spell because he cannot bring himself to kill anyone. He is not a killer.
Delphini "Delphi" Diggory is Voldemort's secret daughter (wow, the Potterverse is turning into a soap opera). She wants to resurrect the Dark Lord—not necessarily to bring evil to the world, but just because she wants to meet her dear ol' dad. It's actually kind of sweet…in a completely evil way.
He is ultimately able to identify the cup as a Horcrux because of his ability to hear the piece of Voldemort's soul contained within them, an ability which is not present in the books. In the film, Harry finds the Horcrux by sensing it due to his status as a proto-Horcrux. He is also able to find the diadem this way.
The author explicitly states that both women were fighting to kill, despite Molly refraining from casting the Unforgivable curse Avada Kedavra. The result of the duel actually comes about as a result of nothing more than spectacular accuracy on Weasley's part.
Voldemort is a master manipulator. By humiliating Bellatrix as he does, he punishes her for her part in the failure at the Ministry of Magic — including her failure to finish off Tonks — and rouses her to try harder to murder members of her family.
She was what Voldemort wanted to be for she was loved, Pureblood, and an aristocrat as well. He probably saw that and her potential and decided to take her under his wing, to make her his. His possession.
Cruciatus Curse ('Crucio')
Harry tried to use this spell himself. The first time was against Bellatrix after she had killed Sirius.
Harry revealed that Draco was still very much alive, and she lied to her master in order to get closer to him. Narcissa may have concealed the truth from Voldemort to save her son, but she inadvertently helped Harry to victory in doing so.
Draco Malfoy's mother Narcissa was cold, cunning and devoted to the Dark Lord. But she was also a mother, which meant she was willing to risk everything to make sure her son was safe. When Harry survived Voldemort's Killing Curse for the second time, Narcissa pretended he was dead so she could get to Draco.
Voldemort can not comprehend love, and so it destroys him to touch Harry because Lily's love for her son runs through Harry's veins and body. ems Harry burnt Quirrell's face when he touched it.
Voldemort's attempts to trick Harry into killing Bellatrix would have done far more harm than good to his sinister cause, as Harry killing Bellatrix might have resulted in dire consequences for him, but he'd remain one of Voldemort's greatest threats and the Dark Wizard would be missing his most trusted lieutenant.
In the book, it's primarily because: Hermione didn't disapparate with Harry and Dobby from Malfoy manner. So it's possible she wasn't close by them. Ron apparated with her based on the description of the scene and not knowing Dobby's injury, he probably took her right back to Shell Cottage without thinking.
Nagini was Lord Voldemort's final Horcrux
Nagini was not only the last Horcrux to be killed, but also the last Horcrux to be created. In an interview, J.K. Rowling revealed that it was the murder of Bertha Jorkins that made Nagini a Horcrux.
Voldemort's reaction towards Bellatrix's death proves that the Dark Lord acknowledged her as his most dedicated follower. The Dark Lord immediately tries to kill Molly Weasley in vengeance before Harry intervenes. Bellatrix was loyal until her death, and was undeniably Voldemort's best and last lieutenant.