Is Avatar Roku Zuko's Grandad?!
Question: Avatar question
Answers: Avatar question
Yes, Avatar Roku is Zuko's Great-Grandfather on his Mothers Side. Firelord Sozin is his Great-Grandfather on his Fathers Side.
Explained to Zuko by his Uncle in "Book 3, ep Avatar and the FireLord
nope. His grandad was Firelord Azulon