April 8, 2013 4:46 PM EDT
I read more in depth and found out. Miraak is origanally The First DragonBorn,the first DragonBorn was (some guy with the first letter of A),and he had children which became other DragonBorn,leading down to the Septims.So your traditionally killing your Great Great Great ... Grandpa.
And the Greybeards did say this "You are the only one revealed to us thus far."