Lord Voldemort

Lord Voldemort is 4 degrees from Blessed John Paul II because Harry Potter is 4 degrees from Blessed John Paul II.  Why the same?  Because they WERE the same person, remember *SPOILER ALERT*, Harry is a horcrux.  Part of Voldemort's soul was with Harry from the time he was 14 months old.  Since the two were separated after Harry and Kingsley Shaklebolt were acquainted, the degrees remain the same.

If he had made different choices,
perhaps Voldemort would have grown
into a handsome and playful guy
like Ralph Fiennes

Instead, Tom became this ugly fellow, the embodiment of evil.