Really, it could have ended with the first book, Harry Potter and the Philosopher’s Stone. But I guess J.K. Rowling really likes to write.
Why do I say it could have ended there? Because, when Quirrell was trying to take the Stone from Harry, “Dumbledore arrived just in time to pull him off” (I’m almost certain that is verbatim from the British version of the book). When Dumbledore arrived, all he had to do was point his wand at Quirrell and cast the Killing Curse. Might I add, Dumbledore had the Elder Wand then. Quirrell did not stand a chance.
However, if the curse killed only Quirrell and not Voldemort, all Dumbledore had to do was point his wand towards the spirit-like form that was Voldemort and cast the Killing Curse – again. It would not have taken more than a couple of minutes. It could all have ended then and there.
But no, Dumbledore had to do what he did and let old Voldy go. This brings us to Harry Potter and the Chamber of Secrets. Nothing to say here and nothing to say for Prisoner of Azkaban either. I am going to jump straight to the face-off between Dumbledore and Voldemort at the Ministry of Magic in Harry Potter and the Order of Phoenix.
Why does every confrontation between good and evil require a dialogue before the actual duel commences? Why did Dumbledore not just say “It was foolish to come here tonight, Tom. Avada Kedavra.” It could have ended right there!! I will reiterate the fact that Dumbledore had the Elder Wand. Does that mean nothing to the man? I have the Elder Wand and I do not play with it because I will not put it down. Dumbledore was already using it so why did he not go all out? Was the “silly wand-waving or incantations” (Severus Snape, Philosopher’s Stone) necessary?
Why did Dumbledore not use one of the Time Turners to go back in time and kill Voldemort (or Tom Riddle, as he was known then) when he went to visit him in the orphanage, like Snape does in this video?
From 2:39 on –