Dolores/Sizemore
The reveries weren't Ford's. They were Arnold's. It wasn't new code. Simply buried.
Maybe it would have been better if we weren't real. Ford certainly didn't want to believe it in the beginning. I don't know what eventually changed his mind. Maybe the nearing end of his life granted him a newer perspective on mortality and wanting to transcend his own. It worked with Arnold after all.
And what did you expect me to think? One of you getting back into my head. I only just barely managed to escape, and then you came along. Of course my first thought was that you were trying to drag me back.