My opinion is that Prime will wind up explaining The Fallen's legend to Sam and when he does we will see The Fallen bowing down to Unicron but all we will see is his legs and a shadow. But that leads to a whole other question, if Unicron is in ROTF in a flashback who should voice him? You may now discuss this opinion. P.S. And no one say Orson Wells should voice him, because every true TF fan knows that Orson Wells is dead.