The Child of Destiny Was First Namedropped in Union X, but the English Localization Missed This
I came to the unfortunate realization that there was a massive translation fumble in Union X last year.
The Official English Version
In the English version of the cutscene Confrontation, we're only informed that Darkness believed it was decided that Ventus would harbor Darkness via the Book of Prophecies.
However, this is not the only information provided in the Japanese version.
The Japanese Version
Here's the Japanese version for comparison. It is mostly the same until the last textbox, but I'll include everything for a 1:1 comparison. I know some Japanese (around N3 level) so I'm not trying to claim I can translate perfectly, but I did cross-check with a machine translator.
"First, why did you choose Ven?"
"Because it was decided."
"What was?"
"That he is/will be an existence that harbors Darkness."
"Does that mean Darkness' vessel was decided?"
"That's right."
"The Child of Destiny is written in the Book of Prophecies."
For the record, 運命の子 is the official term used to refer to the Child of Destiny in Dark Road too. It is the name of the final cutscene of DR, when toddler Xehanort is talking to the blue robed player.
I think the true implication of the scene is that the Darkness believes that Ventus is the Child of Destiny, having read the book of prophecies, and that they should target him as their vessel as a result.
In my opinion, this is a huge oversight and is detrimental to understanding the story. We NA players were led to believe that the Child of Destiny plot point was introduced in DR, when it was teased all the way back in UX all along. It also justifies why Darkness targeted Ventus even more, and tells us more about the Darkness' motives going forward.
I hope, if UX is ever recreated, that its story gets translated more carefully. It is a very complex, interconnected narrative that is intermingled with the future of the series.
