Nathaniel Buzolic: Not Suited to be One of the Original Siblings?

Now that Elijah (Daniel Gillies) is back, he has returned to claim revenge to those people who betrayed him, even his family. Since his character has returned as one of the Original vampires and the brother of Klaus (Joseph Morgan), they also need to fill in the rest of the characters related to him, especially the cast for his original siblings aside from Klaus and Rebekah. But before they can actually choose an actor for the respective roles, they must also undergo the auditions. So how will they choose the actors that will play as one of the Original siblings?