In the book 's climax , PERSON@1 's second Killing Curse also fails and rebounds upon himself , as the result of PERSON@2 's MISC@1 spell , finally killing him , because PERSON@2 , not PERSON@1 , had become the Elder Wand 's true master .

PERSON@1 's second Killing Curse also fails because PERSON@1 used PERSON@2 's blood in his resurrection .
