>>21260442>So, for all intents and purposes, the first time Arceus was made available was in HGSS. What is also wrong, since the event where it was first distributed (from movie 12) was made available in Japan before HGSS were released.It's not wrong because there was an Arceus event for DPPt first (which has no bearing on its "native region" since it's not a wild encounter anyway), it's wrong because there was no Arceus battle in HGSS at all. You have to trade an event Arceus from DPPt to access the Sinjoh Ruins in the first place, Arceus doesn't live there and you can't catch it because it's yours already.
The only wild Arceus is found in the Hall of Origin, and even if it was never accessible, we still have all of the Sinnoh mythology which claims Arceus created Sinnoh. I guess technically it's not native to any region then (but then neither is Deoxys since it's from space) but if you had to pick one, it would have to be Sinnoh. The Sinjoh Ruins aren't even part of Johto anyway, or we'd see where it is on the map, instead of just an arrow vaguely pointing north. Arceus does not live in Johto and never has, end of story.