Voldemort himself created his worst enemy, just as tyrants everywhere do! Have you any idea how much tyrants fear the people they oppress? All of them realise that, one day, amongst their many victims, there is sure to be one who rises against them and strikes back!
“You think the dead we have loved ever truly leave us? You think that we don’t recall them more clearly than ever in times of great trouble?”
Albus P. W. B. Dumbledore