The Avada Kedavra curse, one of the Three Unforgivable Curses in the Wizarding World of United Kingdom.
There was no countercurse. As long as the conditions for casting it were met, a hit meant death. Voldemort, of course, could meet the conditions for casting Avada Kedavra. In both magical power and the desire to kill, he stood at the very pinnacle of Dark Wizards.
Over the course of his life, he had killed countless people with the Killing Curse. Of course, he had killed quite a few with other spells as well.
His only failure had been Harry Potter, who now stood before him. That failure had even left him half-dead for more than ten years. Today, he cast the spell once again, at the very same target.
He believed the result would be different.
And the result was indeed different from last time, but it still was not quite what he had expected.
The Killing Curse could be blocked with other spells. Whether they could hold it off, of course, depended on the magical power of both sides. Given Voldemort's power, very few people alive could block his Killing Curse.
In the United Kingdom, no one except Dumbledore dared claim they could do it.
Although the world called Harry Potter his nemesis, and he had heard that prophecy himself, he did not truly believe it. Yet just as he cast the Killing Curse again, that Potter boy actually cast a spell too.
Harry had actually cast his spell a little earlier than Voldemort. But Voldemort cast so quickly that they appeared to have done it together.
Voldemort's spell was the green Avada Kedavra curse. Harry's, however, was the most basic red Disarming Charm.
Professor Lupin had once taught the students at the Duelling Club that although the Disarming Charm