Sirius's body was most likely destroyed as it passed through the Veil. If the afterlife in Harry Potter even remotely follows real world logic, then it would be a place without mass, matter, or energy as we define them. Sirius was transported to a place where physical body do not and can not exist.
In the film, Bellatrix hit Sirius with the Killing Curse, Avada Kedavra, killing him before he passes through the Veil. In the book, the curse that hits Sirius is not identified, and his being knocked through the Veil is what causes his death.
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.
So book and movies differ somewhat here as in the books it just says Sirius was hit by a curse and fell through the veil but the movie specifically shows him getting hit by the killing curse, but either way, when he fell through the veil he just... dissepeared.
90% here thinks he laughed because he simply lost it, he had a mental breakdown. Though some people believe Wormtail put a laughing charm on him after he blew up the street to make him laugh uncontrollably.
Bellatrix strikes Sirius with a curse, sending him backwards into the veil and to his death.
Harry tried to use this spell himself. The first time was against Bellatrix after she had killed Sirius. His attempt was unsuccessful because, as Bellatrix mockingly explained: 'You need to really want to cause pain – to enjoy it – righteous anger won't hurt me for long…'
5 Bellatrix Lestrange: The Cruciatus Curse.
4 Bellatrix Gleefully Tortures And Murders Her Enemies
She tortures and kills Frank and Alice Longbottom, leaving Neville an orphan, and murders Dobby in The Deathly Hallows.
Sirius Black
"Come on, you can do better than that!" Black loses his battle with Bellatrix and just like that, another member of Harry's makeshift family has died.
In the Harry Potter series, Bellatrix Lestrange used the spell "Avada Kedavra" to kill Sirius Black. It is implied to have been Stupefy, as that was the spell she had been firing most of the fight, as well as the spell that she had just fired at Sirius.
Sirius Black (born November 3, 1959 - died June 18, 1996, aged 36), also known by his nickname Padfoot, is a major character from the Harry Potter series.
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's greatest fear was : abandonment by her Lord Voldemort. Bellatrix is a blind and die-hard servant of her master Lord Voldemort.
Harry makes use of two of the Unforgivable Curses in the books. Dueling with Bellatrix Lestrange, he attempts the Cruciatus curse, with limited results; Bellatrix says that he has to really hate someone to make the Unforgivable Curses work properly, righteous indignation isn't enough.
The darkest of the Dark Arts, Harry Potter unforgivable curses are the Cruciatus Curse, the Imperius Curse, and the Killing Curse. Although the curses are highly illegal, Harry using Unforgivable Curses happened, but he uses them once he was thrust into the Second Wizarding War.
Ginny and the Bat Bogey Hex
As the youngest Weasley, we're sure Ginny observed more than her fair share of unpleasant spells over the years but it was the Bat Bogey Hex she was famous for – and with good reason.
1 Avada Kedavra Is Just Ridiculous
Only love itself, the strongest magic of all, can block the Killing Curse. Lord Voldemort cast this spell constantly in his lifetime, and it's the spell that killed Harry's parents in particular.
The three Unforgivable Curses in Harry Potter are Crucio, Imperio, and Avada Kedavra, and all three are available to Hogwarts Legacy players. Crucio subjects the victim to extreme torture, while Imperio puts them under the control of the spellcaster.
In Deathly Hallows, Hermione faced a real test of her physical and psychological stamina. 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.
Why Harry Didn't Cast Avada Kedavra. Despite Harry Potter using Unforgivable Curses, one of the Unforgivable Curses Harry Potter never used the Killing Curse for several reasons. Avada Kedavra was Lord Voldemort's signature spell.
Why did they mute Harry's scream? They muted Harry's scream when Sirius died because it was so heartbreaking that Helena Bonham Carter (Bellatrix) and Emma Watson (Hermione) cried. It was too sad to watch, so they muted the scream. Going silent for that makes the scene more amazing.
Harry became so enamoured with the spell that he eventually used it to finish off Lord Voldemort. Here's how Harry's relationship with Expelliarmus became his signature – and why that's a good and bad thing.
In Harry Potter And The Deathly Hallows Part 2, Voldemort kills Snape using his snake Nagini instead of his favorite spell Avada Kedavra - here's why. Voldemort killed Snape in Harry Potter And The Deathly Hallows Part 2 using his Horcrux snake Nagini instead of his favorite Unforgivable Curse, Avada Kedavra.
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.