....argument is better put on other threads but basically it goes two wands with the same cores will not attack each other hence the priori incantatum incident.
Dumbledore said:"But -- I stopped Sirius and Professor Lupin from killing Pettigrew!
That makes it my fault if Voldemort comes back!"
"It does not," said Dumbledore quietly. "Hasn't your experience with the
Time-Turner taught you anything, Harry? The consequences of our actions are always so complicated, so diverse, that predicting the future is a very difficult business indeed.... Professor Trelawney, bless her, is living proof of that.... You did a very noble thing, in saving Pettigrew's life."
Dumbledore. PoA said:But remember this, both of you: you must not be seen. Miss Granger, you know the law -- you know what is at stake.... You -- must -- not -- be -- seen."
PS/SS said:Harry tried. And tried. He had no idea what Mr. Ollivander was waiting for. The pile of tried wands was mounting higher and higher on the spindly chair, but the more wands Mr. Ollivander pulled from the shelves, the happier he seemed to become.
"Tricky customer, eh? Not to worry, we'll find the perfect match here somewhere -- I wonder, now - - yes, why not -- unusual combination -- holly and phoenix feather, eleven inches, nice and supple."
GoF said:"And now - we duel."
Voldemort raised his wand, and before Harry could do anything to defend himself, before he could even move, he had been hit again by the Cruciatus Curse. The pain was so intense, so all-consuming, that he no longer knew where he was. . . . White-hot knives were piercing every inch of his skin, his head was surely going to burst with pain, he was screaming more loudly than he'd ever screamed in his life -
And then it stopped. Harry rolled over and scrambled to his feet; he was shaking as uncontrollably as Wormtail had done when his hand had been cut off; he staggered sideways into the wall of watching Death Eaters, and they pushed him away, back toward Voldemort.
"A little break," said Voldemort’s, the slit-like nostrils dilating with excitement, "a little pause . . . That hurt, didn't it. Harry? You don't want me to do that again, do you?"
GoF said:A jet of green light issued from Voldemorts wand just as a jet of red light blasted from Harry's - they met in midair - and suddenly Harry's wand was vibrating as though an electric charge were surging through it; his hand seized up around it; he couldn't have released it if he'd wanted to - and a narrow beam of light connected the two wands, neither red nor green, but bright, deep gold. Harry, following the beam with his astonished gaze, saw that Voldemort's long white fingers too were gripping a wand that was shaking and vibrating.
PS/SS said:"I'm sorry to say I sold the wand that did it," he said softly. "Thirteen-and-a-half inches. Yew. Powerful wand, very powerful, and in the wrong hands... well, if I'd known what that wand was going out into the world to do...."
He shook his head and then, to Harry's relief, spotted Hagrid.
GoF said:"Exactly," said Dumbledore. "Harry's wand and Voldemorts wand share cores. Each of them contains a feather from the tail of the same phoenix. This phoenix, in fact," he added, and he pointed at the scarlet-and-gold bird, perching peacefully on Harry's knee.
"My wand's feather came from Fawkes?" Harry said, amazed.
"Yes," said Dumbledore. "Mr. Ollivander wrote to tell me you had bought the second wand, the moment you left his shop four years ago."
There will be more to it than that, what with so many others kicking around - I think Harry will end up working himself up to the deed but will need someone else to distract Voldy at a key moment- a phoenix, wand memories, golden statues animated and other wizards to help, the usual aids...
Then they are not really shaking hands, are they? I would love to see him lose his powers as a wizard and forced to live as a muggle though.
You forgot to add one more catagory. Alz's favourite.
Harry will turn out to be a horcrux too, and in process of destroying him, Voldemort will get blasted again. This time not returning because all the rest of the horcuxes would have been destroyed.