I had thought about that line, but I don’t know even you can even get an isolated version of that line.

“Your coming together will be your undoing… in about 5 seconds…”

The thing is, if Palpatine knows, would he tell Kylo to bring Rey to him instead of killing her? And if you make that change, how do you differentiate Kylo’s goals from Palpatine’s? Kylo also wants Rey to come with him to face Palpatine, so the distinction is pretty muddy.

Maybe if you made Kylo’s motivation be to prevent Rey from reaching Palpatine, because Kylo knows Palpatine likely has some trick for them up his sleeve.

So change Palpatine’s line to something like, “Bring the girl.”

Then later, Kylo: Palpatine wants you… but I have other plans.

Kylo: We’re a Dyad in the Force, Rey. Two that are one. We’ll destroy the Sith, and take the throne.
(Palpatine wants to be killed, so Kylo’s like could be more ambiguous to imply that they’ll find a way to destroy him for good)

Then later you cut Kylo’s line, “The only way you’re getting to Exegol is with me.” Because he doesn’t want Rey to go to Exegol. He just destroys the Wayfinder without saying anything.