>>53777432I remember a little Japanese fan theory that Arceus was a bastardization of Regigigas from ancient settlers who invaded Sinnoh later than the regi worshippers. They have the same white and gold color scheme, as well as having created three children from the matter of our world. The idea was that “defeated giants” as stated in the plates referred to the Arceus worshippers defeating the Regi worshippers, with Regigigas being subsequently sealed away. The idea included how Arceus’s connection with the Unown came from the Johto and Sinnoh settlers meeting one another, as was stated in HGSS, implying the belief of the people could trigger actual divine connections.
The same theorist had some other ideas that actually ended up becoming canon in PLA years later, so I can’t exactly call them totally off-base. Even Cynthia implies in the game that Dialga/Palkia’s power may have simply convinced ancient people that they ruled over timespace.