>>57164264>did the plot even go anywhere with the DLC?At the end of the DLC Terapagos calls the professor in to the crystal pool at Kitakami. Only, then it gets weird.
The professor claims they're from a parallel timeline to this one and was building a time machine to connect to other realities, and trade you their copy of the Scarlet/Violet Book for your copy of the White Book, a tome written by Professor Briar detailing your adventures in Area Zero. The professor then returns to their own time. Only, here it gets weird.
If you go to the professor's sub-lab in the Area Zero Underdepths, you can find a copy of the White Book. The professor's notes there say they were pulled out of time to a mysterious place and met a child, who they traded books with. This implies the professor was called from the past. But if the professor traded their copy to the protagonist they wouldn't have it to embed their ID card in to operate the time machine later, the copy that Arven had in the lighthouse lab at Cabo Poco. Hence, a temporal paradox. If you simply traded with a parallel universe's professor the paradox is resolved, but then it doesn't explain the White Book in the Underdepths.
Moving on from that, according to the professor the "past" and "future" the time machine connects to are alternate timelines where all Pokemon are "past" and "future" versions. This means that Iron Moth and Slither Wing are both alternate versions of Volcarona instead of a distant descendant and ancestor, respectively.