He was incapable of love for the reason that he got no love or acceptance, ever, from anyone and he would never have got were it not for Bellatrix. So, she was unexpected, the exception. He still didn't love her truly or sacrificially or purely because he wouldn't die for her (but he would certainly kill for her.
Voldemort Respected Her
However, he had a lot of respect for her and recognized how valuable she was. 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.
He did not love anyone, and did not care to be loved. He felt nothing for his family, and only wanted his friends in school to rally around him because he wanted to hold power over them. Bellatrix Lestrange was obviously in love with him and worshiped him, but he only cared for her servitude, not 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.
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.
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.
IN "CURSED CHILD", SHE AND VOLDEMORT HAD A DAUGHTER
Harry Potter and the Cursed Child dropped a major revelation: Bellatrix and Voldemort have a secret illegitimate daughter together. That means Bellatrix cheated on her husband Rodolphus.
As much as Bellatrix loves Lord Voldemort, she equally hates Harry Potter, considering him the greatest threat to Voldemort and his plans. She will do anything to assist the Dark Lord's desire to defeat Harry.
The 'boy who lived' aka Harry Potter, aka Daniel Radcliffe had a crush on Helena Bonham Carter, who starred as Death Eater Bellatrix Lestrange in the film. During the reunion, Daniel revealed that he had a crush on her and even wrote a letter to her.
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.
Bellatrix used a powerful "love potion" on Voldemort and they have sex while he is temporarily obsessed with her. She then uses obliviate on him while he sleeps (you know, he falls asleep after his post-sex cigarette) and tells everyone that the baby is her and her husband's.
But in 1998, the battle of Hogwarts, Voldemort was 70/71 while Bellatrix was 47, and i think Avery was quite young too?
Bellatrix Lestrange (née Black) is the first female Death Eater introduced in the books. Aunt of Draco Malfoy and Nymphadora Tonks. She was introduced in Harry Potter and the Order of the Phoenix. She is the most faithful member of Voldemort's inner circle.
Cruciatus Curse ('Crucio')
Harry tried to use this spell himself. The first time was against Bellatrix after she had killed Sirius.
Delphi was conceived from a liaison between Voldemort and Bellatrix. She was born at Malfoy Manor, shortly before the 1998 Battle of Hogwarts. 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.
After being on the run from a bunch of Snatchers, the gang were taken to Malfoy Manor, where Bellatrix proceeded to torture Hermione using the Cruciatus Curse. It was a testament to Hermione's toughness that she was able to walk away without lasting damage.
Bellatrix's evil nature arises from her blind devotion to Tom Riddle and she is cruel. She enjoys torturing people and is quite frankly, insane. However, she is not as evil as Voldemort as he has transcended beyond limits of evil and dark magic by making not one but 7 Horcruxes.
Bellatrix Lestrange was in constant competition with Severus Snape for Voldemort's attention. She was jealous of his magical potential and never trusted him.
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.
Bellatrix is approximately mid 40s in her first appearance and dies at about 46/47. Helena first played the role at age 41, and last played her at age 45, meaning there is only a two or three year difference.
The brilliant Helen McCrory, who played Narcissa Malfoy, had initially been cast as Bellatrix but had to pull out after becoming pregnant.
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.
None of the good guys dare use the Killing Curse throughout the events of the movies and books, no matter how high the stakes and how difficult things are. But Ron Weasley is the exception, giving it a go in the Deathly Hallows: Part 2 movie when himself and Hermione look destined to die via Nagini.
So, Voldemort had to kill Snape for the wand's allegiance to switch. Voldemort knew he couldn't cast Avada Kedavra with the Elder Wand to kill its master, so he ordered Nagini to be the one who killed Snape. In reality, the Elder Wand belonged to Draco, as he was the one to disarm Dumbledore in the Astronomy Tower.