What if Palpatine created Rey, as he created Vader, but he used Kylo and Snoke in the prior two movies to lead her to the dark (so she’d make a powerful host). They put her under pressure, put the people she cared about under threat, so she’d turn in desperation to the easier, seductive power she has within reach.
Snoke, who is basically Palpatine, was clearly intent on having Kylo kill Rey, one of his last attachments, in TLJ after he finds out she’s attained the spirit of a true Jedi. And then Kylo murders Snoke instead. So I think we’ve sort of reconciled the idea already that he changes directions once he finds out neither of his heirs are particularly psyched about being evil Sith Lords. Both Kylo and Rey are conflicted. It makes sense that he’d have them fight each other so they last one standing is engulfed by the dark side.
Oh, and I think this would be the best line for Luke: "Because you’re a Palpatine? He has no claim to creations of the Force.” But I can go back to the other one if we find it more appealing.