“Does Voldemort know when a Horcrux is destroyed, sir? Can he feel it?” Harry asked, ignoring the portraits.
“A very interesting question, Harry. I believe not. I believe that Voldemort is now so immersed in evil, and these crucial parts of himself have been detached for so long, he does not feel as we do.”
So why does Voldemort (and possibly the childlike figure in “Kings Cross”) faint when Harry is killed?