With that in mind, it's best to think of Dumbledore's statement, "You are not a killer," in this way: "Draco, you are not a killer; you have not killed anyone yet, and you don't have to. The choice is before you.
He knew that Malfoy was behind the poison and the necklace, as he mentions this to Malfoy right before he dies: “Oh yes, I do,” said Dumbledore mildly. “You almost killed Katie Bell and Ronald Weasley. You have been trying, with increasing desperation, to kill me all year.
Voldemort knew Draco couldn't kill Dumbledore so he was going to kill him. Dumbledore didn't want him dead and if he managed to reach till Dumbledore he didn't want him to feel the conscience of killing someone.
Did Harry Potter's childhood arch nemesis, Draco Malfoy, ever feel any guilt or remorse for letting the Death Eaters into Hogwarts and setting the table for Albus Dumbledore's death? Almost assuredly; it was in the Astronomy Tower that Draco came to terms with the fact that he was no killer.
Originally Answered: Why did Dumbledore plead with Snape? Dumbledore knew Snape didn't want to kill him and was afraid that Snape would still refuse to do so, and would then be killed by his Unbreakable Vow.
Dumbledore's last line is very similar in the final book and movie. He tells Harry in the film, "Of course it's happening inside your head, Harry. Why should that mean it's not real?"
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's refusal to reveal Harry's identity to Bellatrix was not because he liked him. It was because he believed that Harry was the only chance they had at defeating Voldemort. At first, Draco admired and revered Voldemort until he threatened his family's safety.
Specifically, Draco was jealous of Harry. It was easy to miss because Draco didn't often show his emotions, modelling himself on his cold, confident, calculating father, but J.K. Rowling has confirmed that a lot of his enmity towards Harry stemmed from envy.
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.
Gaunt's ring
After retrieving the ring Albus Dumbledore himself fell victim to a curse that, even when contained, would likely have killed him within the year. Once rendered defunct as a Horcrux, the stone was placed inside a Golden Snitch and left to Harry Potter in Dumbledore's will.
At the end of Book 6, “Half-Blood Prince,” Draco disarmed Dumbledore before Snape killed Dumbledore. “And that meant he conquered him, even though Dumbledore was very weak at the time, he was very ill. He was on the point of collapse when it happened,” Rowling said.
She asked him because if Draco was still alive, she had something to fight for. She had a reason to lie to Voldemort. If Draco is alive, she needs to get into the school to see him and protect him, and helping Harry feign death was the easiest way to do that. But if Draco was already dead, she wouldn't have bothered.
Severus Snape killed Hogwarts Headmaster Albus Dumbledore because he had been asked to do so by Dumbledore himself. Dumbledore found out about Draco's task to kill him and so asked Snape to do it instead.
The pressure of being in the Slytherin house and being the son of a death eater, all that stuff. ... Because Draco could not face what he had to do to save himself and his beloved parents from death. He realized more and more how much he dreaded to have blood on his hands.
She was remorseless and was cackling in glee after she had murdered Sirius. Bellatrix couldn't stop raving about it and showed it by singing “I killed Sirius Black” multiple times.
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…'
Narcissa's greatest moment, however, was when she chose to betray Voldemort in Harry Potter and the Deathly Hallows. Not knowing whether Draco was alive or dead, Narcissa chose to lie to the Dark Lord rather than risk losing her son.
Snape dismissed the curse as bearing no change to her appearance, causing Hermione to flee in tears. We knew Snape wasn't exactly chummy, but this was a real tipping point.
Erroneously believing Snape is the master of the Elder Wand and that Snape's death will make him the master of the Wand, Voldemort kills Snape by having his pet snake Nagini bite him through the neck.
He truly believed the Elder Wand had to be passed down through murder, because that is what the legends say. But even if he knew that one only had to be disarmed, Voldemort was still too arrogant to do that. He kills anyone in his way.
Sectumsempra is a curse invented by Professor Severus Snape, during his childhood, when he was known as "The Half-Blood Prince". He created it with the intention of using it against his enemies, and it soon became one of his specialties.
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.