Snape killed Dumbledore in an effort to protect Draco Malfo and spare him from the emotional trauma of murder. Snape used the Killing Curse (Avada Kedavra) to kill Dumbledore and end his suffering.
The Headmaster's brilliance is practically limitless; more importantly, there are brands of magic that he would never resort to, regardless of the situation. He could have theoretically defeated Voldemort with a simple Avada Kedavra, but he chooses to err on the side of compassion, instead.
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.
Draco Malfoy was not the one who killed Albus Dumbledore, as Severus Snape intervened. Still, he did become the rightful owner of the Elder Wand after disarming the powerful wizard. Draco was unaware that he was the true owner of the Elder Wand at that moment and never wielded it.
However, Draco was ordered by Voldemort to kill Dumbledore. Lestrange saw this as an opportunity to test Snape's loyalty and while making this vow to always watch over Draco, Lestrange forced Snape to agree to killing Dumbledore himself in case the youngster was unable to do so.
Why Snape's Avada Kedavra Was BLUE When He Killed Dumbledore - Harry Potter Theory
Why did Snape kill Dumbledore if he was good?
Summary. As a character, Severus Snape was often misunderstood. Many believed he was a villain, and weren't convinced he was actually working for Dumbledore. Snape killed Dumbledore in an effort to protect Draco Malfo and spare him from the emotional trauma of murder.
He attempted to kill Dumbledore, but Dumbledore tried to convince Draco not to perform the task. Draco said that he had no choice. Otherwise, Lord Voldemort would murder him and his family. Dumbledore told Draco that he shouldn't do this, and that Draco was not a killer.
He concludes that, because Snape killed Dumbledore, the Elder Wand belongs to him. Voldemort knew he couldn't cast Avada Kedavra with the Elder Wand to kill its master. Voldemort had to kill Snape because he needed the wand's allegiance to switch.
Harry later learns that Dumbledore was already dying and had asked Snape to be the one to kill him when the time was right. In the end, Snape wasn't a villain. He remained loyal to the headmaster while also saving Draco per the vow he made.
It is this misguided belief that motivates Voldemort to act as he does. The film differs from the book in its portrayal of the method used to kill Snape, but neither uses the killing curse for the simple reason that the Elder Wand is said not to be able to act in direct opposition to its master.
One of the three Unforgivable Curses outlawed under wizarding law, Avada Kedavra kills the victim on impact, instantaneously and painlessly, usually with a blinding flash of green light. There is no way to block the spell, and there is no counter-curse - it can only be dodged.
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. In 1707, the Wizards' Council was restructured into the Ministry of Magic, which allowed for more strict restrictions on certain types of magic.
The morally ambiguous character's death was significant in Harry's story and led to the reveal that Snape had been working to protect Lily Potter's son all along. Though Snape's Pensieve memories revealed the whole truth, his love for Lily was covertly foreshadowed in his final moments.
It is also said to be a fairly complicated spell. It depends on a persons willingness to kill someone and also the power behind the wand. To quote Barty Crouch/Mad-Eye Moody in 'Harry Potter and the Goblet of Fire', “Avada Kadavra is a curse that needs a powerful bit of magic behind it.
It did backfire on Voldemort but just not the degree it did the first time. It failed to destroy his body because it killed the piece of hit soul that was in Harry forming the horcrux but it did knock him off his feet and actually rendered him senseless.
Simple answer is, that's only in the movies. They often play fast and loose with things that might look or sound cool in the moment but make no sense in the overarching story. Ron never casts Avada Kedavra at Nagini in the books.
It's implied that Septum Sempra is Snape's own creation, that he used a specific counter-curse to heal Draco, and that the spell isn't designed to be instantly fatal, but to inflict a gruesome, but relatively slow death if left untreated. It's likely Snape is the only person who knows said counter-curse.
This was one of the incantations that was part of the necromancy ritual that Grindelwald used to revive the Qilin. Severus Snape used this spell to save Draco Malfoy after he was attacked by Harry Potter using Sectumsempra. He then took him to the Hospital Wing for further treatment, hoping to avoid scarring.
Draco is in his own house. He is his godson and the child of his good friend Narcissa and fellow former death eater Lucius. He is fond of Draco if you could call it that. He doesn't like Harry at all.
According to the films, Hedwig's killer might have been Selwyn, who was known to be pursuing Harry and Hagrid at the time since Hedwig's death in the film happened quite a while into the fight when there was only a couple death eaters following them, or it might have been Stanley Shunpike under the Imperius Curse.
Voldemort told Snape he had been a faithful servant, but that he had to regrettably kill him, as he mistakenly believed he was the master of the Elder Wand, as Snape had killed Albus Dumbledore, its former owner the year prior, during the Battle of the Astronomy Tower.
J.K. Rowling says Draco doesn't have a patronus because he never learned the spell but I think it's because he doesn't have any powerful happy memories to use. He has tons of happy memories... He had an amazing childhood. However, she also said Snape was the only Death Eater who could produce a Patronus.
So, during the summer between his fifth and sixth years at Hogwarts, Draco Malfoy was tasked with the assassination of Albus Dumbledore to restore his family to Voldemort's good graces. Also at this time, Draco was branded with the Dark Mark.
Family. Snape's family background is mostly shown in flashbacks during the course of the last three novels. Snape was born to Eileen Prince, a witch, and Tobias Snape, a Muggle, making him a half-blood (hence the name, "Half-Blood Prince").
