GOF said:For a fleeting instant, Harry thought he saw a gleam of something like triumph in DD's eyes. But next second Harry was sure he had imagined it, for when DD had returned to his seat behind the desk, he looked as old and weary as Harry had ever seen him.
A lot of people are debating this scene in various threads here. If this has its own thread, my apoligies, and merge this one.
I think it was the use of Harry's blood that gave DD the gleam of triumph in his eyes. I think by doing this, Voldemort may have negated the blood protection that his mother gave him. But by doing so, he also became in debt to Harry. I think that if Voldemort killed Harry, he will die too.
Or we may have a scenario like the one shown in War of the worlds. The aliens doomed themselves once they ate and drank on earth. They were not used to with all the bacteria and other germs that we are.
Voldemort is not used to the feeling of love and loyalty and bravery. That blood might wear him out eventually.
What do you guys think?