Did Voldemort create Avada Kedavra? Nothing is ever said about the inventor of Avada Kedavra, but it was invented before 1717, because it was classified as an Unforgivable Curse by the British Ministry of Magic then.
The Killing Curse was created in the early Middle Ages by Dark witches and wizards. Primarily, the curse was used to quickly slay opponents during a duel.
Lord Voldemort likely invented some of the protective spells he used in the hiding places of his Horcruxes, such as the Gaunt Shack and the Horcrux Cave. These spells were extremely dark in nature and extremely difficult for even Albus Dumbledore to penetrate sometimes requiring the aid of another wizard.
Avada Kedavra
J.K. Rowling has spoken about the root of this spell. According to Rowling, its root is actually Aramaic and derives from the original "abracadabra," which means "let the thing to be destroyed." In this case, the thing is a person.
Avada Kedavra meaning
Used mostly by Lord Voldemort and his Death Eaters, it's used to kill people. Rowling claims she created this spell out of a popular “Abra-Kadabra” saying in Aramaic which means “Let the thing be destroyed”.
In order to conjure the avada kedavra curse, you have to want to kill your victim. We all know that Voldemort could easily kill a child without an ounce of remorse... but not Snape. Snape didn't want to kill Dumbledore, and this was why the spell was blue instead of the usual green.
Though Harry encountered many opportunities that deemed Avada Kedavra necessary, it remains as one of the Unforgivable Curses Harry Potter never cast. For one, he viewed the spell as an immoral practice commonly used by users of the Dark Arts.
The only clear canon instance of a good wizard using Avada Kedavra to kill is Snape's euthanasia of Dumbledore.
Why didn t the Death Eaters use Avada Kedavra all the time? Firstly according to the fake Moody Avada Kedavra (AK) requires a powerful magic. Therefore using it repeatedly would be magically - and perhaps even physically - very draining. Secondly Death Eaters don't always want/need to kill their targets.
Avada Kedavra
It's used to kill people, it's an Unforgivable Curse, and it was Voldemort's favourite, so it's going last.
The killing curse (Avada Kedavra) was a tool of the dark arts and one of the three unforgivable curses. It was one of the most powerful and scary spells (if not the scariest) that wizards have known.
Hermione Granger
Her wandless magic can be seen prominently in The Half-Blood Prince. She performs Confundus on Cormac McLaggen simply by whispering into her hand. She also successfully performs Avis and Oppugno Jinx without the use of her wand when sending birds to attack Ron.
She stared Bellatrix down and challenged her to a one-on-one duel. Molly Weasley had hit Bellatrix Lestrange straight in the heart with an unspecified spell and killed her on the spot. Since Avada Kedavra is an unforgivable curse, many fans have argued that it is not what Molly used.
He is also revealed to be a double agent for Albus Dumbledore and the Order of the Phoenix. But many people forget that he also invented a number of spells. In the Harry Potter movies, Snape came up with the Sectumsempra curse when he was a student at Hogwarts, and it's known to cause painful lacerations on the target.
Phoenixes were semi-protected from the Killing Curse, due to them being immortal. In 1996, Fawkes swallowed one intended for Albus Dumbledore, causing him to burst into flame and die instantly. However, he then was reborn from his ashes. This makes phoenixes resistant to the Killing Curse.
Hogwarts Legacy's Ranrok Dragon is Technically Not 'Alive'
There will likely be fans upset that the final boss cannot be dealt with instantly with Avada Kedavra, but because the curse only canonically works on living beings, Hogwarts Legacy may have found some clever wiggle room with Ranrok Dragon.
Its incantation is Avada Kedavra. The only known counter-spell is sacrificial protection, which uses the magic of love. However, one may dodge the green bolt or block it with a physical barrier.
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.
Avada Kedavra, also known as the Killing Curse, kills a person instantaneously and without injury. There is few counter for it, and only one person, Harry Potter, has ever survived it with Sacrificial Protection that has been endowed upon Harry Potter by His Mother Love for Him.
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.
Defeating The Dark Lord with his signature spell
Disarming is about defence, not murder. Voldemort was a killer, Harry was not. It was an important distinction for Harry, who had learned so much about Voldemort and seen first-hand the ways in which they were similar.
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.