Glad you like it. It’s kind of like Palpatine’s trying to pick his own ‘Chosen One’ as he did before, this time from two candidates, not realising that they’re one together, and it’s the Rey-Kylo ‘unit’ that can defeat him (and ultimately, actually, empower him, because Dyads of your own creations are delicious). Once again, Palpatine’s the master manipulator but the Will of the Force has the last laugh.
Plus, Kylo’s right about Rey, and right about what they can achieve. But if they’re both the same yinyang - Kylo with light in his dark, and Rey with dark in her light (or the other way around), it leaves room for them to achieve some kind of viable balance. It also adds a bit more jeopardy to Rey’s final fight - facing Palpatine alone (a very Luke thing to do) isn’t going to work here - but then Kylo shows up after all, his spirit more pure. And sure, Rey and the Jedi destroy Palpatine (great light destroys great dark), but Kylo was still a key part of that process.