So, the entire game, we've been told about two mythical beings: The Black Monster and the Moon Child. The Moon Child is a child born every 108 years when The Moon That Never Sets (so called because it never moves in the sky) glows red. It is said that it is meant to purify the world, and the Black Monster opposes this purity, and kills the Moon Child and everyone around it. There's a lot to unpack with this tale, but there's one thing that is important to the question: The Moon Child has a hypnotic effect on all who behold it, causing them to rally around to protect the Moon Child to their very last breath and beyond in order to bring about a new god to the world.

At the end of Disc 3, you get the big plot twist: one of your party members is the Moon Child, and another is the Black Monster. I'll keep the spoilers light, and won't reveal who is who, but it's something you should have twigged well before that point.

And it's here where the question comes in. See, throughout the game, the characters have all been motivated to protect the Moon Child well before they even knew they were the Moon Child. All the characters who talk about them want to keep them safe or are attracted to them, to the point that a guard is nearly pulled away from his post at the mere sight of them! And so comes the question: is the party under the spell of the Moon Child? This is a question that is never answered, but it's tantalizing, isn't it? The very idea that the party itself is motivated by an unseen force that isn't their own will, even as they are the saviors of the planet? Because even after this point, their goal is not to protect the world from the villain. The Moon Child has been kidnapped by the main villain this point, and the party's biggest motivation is to rescue the Moon Child!

Not only is this question never answered, it's actually never even addressed! It's only when you start thinking about the plot in context does the question even open up, and THAT is a showing of a genius story writer. When a question is left unanswered, that's usually bad. But when the question itself is interesting enough? That lets a story live far beyond its reach.