In an effort to use this blog more I'm going to start posting a LOT more of my Pokémon related ramblings here!! Please note this is going to be a long(ish) post, mostly analyzing what we know about Sinjoh and the Celesticans / ancient people who resided in Sinnoh via the Johto games.
*Please note that anytime in this post I mention Johto I'm referring to HGSS Johto, and not the original second generation. Also note this is about primarily about HGSS and PLA lore wise!! I'm not giving my opinion on gameplay aspects here, that's like a whole separate can of worms I'm not going to get into right now LMFAO.
The regions of Hisui, Sinnoh, and Johto are so linked together that it's genuinely hard to fully understand one without knowing about the others I've realized, hence me making this post! Now, this is mostly an analysis of the Sinjoh ruins event specially in correlation with Legends Arceus. Once again, there's a lot more linking Johto and Sinnoh (like them being the only regions with Unown being as prominent as they are), but this is primarily about the Celestican people.
The other day I was trying to work out a personal timeline of the Pokémon games when I remembered the infamous Sinjoh ruins event. This event in general is creepy as hell, especially since it's so hard to access legitimately. Not to mention the spooky implications of being shown real life images of cells, space, and real world locations in a 2d children's game.
Yes, this is very important. And yes, this is incredibly freaky. But as I was reanalyzing this, I came to a very startling realization that a lot of people forget about Cynthia's VERY important dialog prior to that. She, quite literally, spells out what happened to the original Celestican people we hear about in Legends Arceus.
Now, stay with me here. In the 12th old verse, Sinjoh is mentioned. Which is INCREDIBLY important. These verses are written by one of the original Celestican people as we see in verse 5, when they state "our name", and "our people". (I personally believe they were written by Cogita, but that's not important here. Only important part is the writer has a solid link to the Celesticans.)
Now, we have to take a look at Cynthia's dialog in the ruins event. She originally says she mistook Sinjoh FOR Sinnoh, deepening their link even further. Now even further on when you enter the ruins, she states the original purpose for the ruins. They were built in favor of Arceus, and they hosted songs and various other celebrations of it here. And that the people that built it came from Sinnoh a long time ago.
Also, what's important to mention is she states these traditions are STILL BEING PASSED DOWN! Now, I don't doubt these have likely significantly changed over time, but this is such an IMPORTANT piece of dialog even I glossed over at first! Especially with the time it released! Back then, this was one of the only mentions of ancient Sinnoh. And once again, right after that we see one of, if not, the SCARIEST cutscene in the entire franchise.
There's many direct links to the Celesticans and them worshipping Arceus, but the most blatant is the flavor text given to Volo's outfit in Legends ZA, which are especially important considering he has links to them as well, as he's a direct descendant of them! Below are screenshots from my own game.
Now, I won't claim to know what caused them to move to Sinjoh, or if anything else happened. But their descendants are STILL OUT THERE, not just Cynthia like I formerly thought!
This isn't the only link between Sinnoh and Johto either, but it's by far the most important and I, personally, believe is NECESSARY to understand what happened to the Celesticans in Legends Arceus. This event is physically IMPOSSIBLE to disregard.
If you read all the way down here, thank you so much!! This took quite a few hours of scouring Bulbapedia, games, etc. And I had a lot of fun writing it all out!! Hoping this helps other people out there like it did me because it's so easy to miss.