“Why did the Emperor come for me?”
“Because none of his clones could survive hosting his spirit. So like Vader before you, he influenced the force to create life. You… are Palpatine’s heir.”
"He sees you as a true Palpatine, created to inherit the throne of the Sith. But what he doesn’t know is that we’ve become a dyad in the Force, Rey… two, linked by the raw power our families share. We can end him and the Sith, and create something new, together…”
This also works to convey the truths that Palpatine would have told Kylo Ren (both to seduce him and to get him to bring Rey to him), whilst retaining the parts of the plan that Palpatine would have kept secret (spirit transferrence into a host) that he’d act on when he had Rey available.