[That's ... unacceptable. There can't be a world without Noct. But simply saying so wouldn't be enough. He knows that much. So he takes a minute to move past the kneejerk reaction and think about the question.]

What's to say they wouldn't just choose another One? If Regis doesn't have a kid, they could choose Regis himself. Or Luna? Or Ravus? Or ... anyone they wanted.

Or ... What if there is no Chosen One, and they just let the world go dark? I mean, do they even really care if they're letting it happen in the first place?