Just consulted the novelization, and there is no direct equivalent line at that point, no “you’re just a clone” or anything like that. But, there’s a line from Hux as he and Pryde watch Kylo mow down posers on Mustafar that, “Flames of rebellion burn across the galaxy and Kylo Ren chases a ghost.” I think “phantom” risks being rather on the nose given the official title of Episode I. The fewer words the better, also. We don’t want it to come across as a nerdy insert, despite that being what it is.

That’s why I prefer, “You’re a ghost, in a rotting clone. What could you give me?”