>>58625924Replying mostly because I find it interesting how people are interpreting Volo, and I thought I'd add some extra context. (LONG POST AHEAD)
I've been going through various reviews and analyses of PLA lately and have come across some fascinating interpretations from Japanese players. Looking at the game through the lens of Japanese history, apparently PLA's setting has a lot in common with Hokkaido during the Meiji Restoration. In particular, the Celestica people bear some resemblance to the indigenous Ainu people through this lens.
This part of history is apparently an uncomfortable topic in Japan and would probably be too brutal for a game aimed at kids, so it makes sense that it would be kept vague (assuming this is what Game Freak was aiming for). But with this context, we can read between the lines for a lot of in-game lore, and things become quite ominous. We're never given much information on what happened for the Celestica people to disappear from their homeland. We're told in one of the Old Verses that the Diamond and Pearl clans eventually settled in Hisui and claimed to be the original Celestica people who worship the "almighty Sinnoh". But how did these clans learn terms like "Celestica people" and "almighty Sinnoh"? My headcanon is that they must have had some sort of interaction with the Celesticas, and considering the fate of the Ainu people, the situation becomes a lot darker.
Basically, as a member of the original Celesticas, Volo might have experienced the brutal colonization of his people at some point, leaving him isolated. The being he and his people worshiped, Arceus, never came to their aid---his deep-seated hatred would be a lot more understandable if this were the case. Also, considering his very long lifespan, he would've been forced to carry these agonizing memories for a long time, making his "gift" of immortality seem more like a curse.