>>20493371I have an autistic fascination for this sort of shit. I haven't been able to fit Xerneas/Yveltal into it yet though, because I don't know anything about Xerneas at all.
Arceus and the creation is (mostly) influenced by Taoism: In religious Taoism, the One (with one hell of a title: "Heavenly King of the Chaotic Never-ending Primordial Beginning" is one translation) comes into existence out of nothingness, and then proceeds to create Two, who incidentally oversees time. And from Two comes Three (though some people disagree on this). In any case, people over at GF probably separated the One into two Pokemon: Arceus (the central deity/the king) and Palkia (because the king is said to hold the pearl of creation and resides over all celestial layers, planets, stars etc., which sounds like Palkia's job.).
Also, the One creates the first writing system by watching the universe, which my headcanon says is Unown. He's said to have cast them into gold and jade, hence Arceus' color scheme. They might have been influenced by some other mythologies, because Giratina doesn't really have a place in Taoism and is more like Satan, obviously. The Three is basically the Taoist Jesus as he likes to spawn into our world and actively participate in the human realm, which doesn't sound like Giratina.
The division between the creation trio/those elves make me think they might have been influenced by the division of heavenly chi (Arceus) / earth chi (the creation trio) / human chi (elves) in Taoism. The creation trio probably created the "god Pokemon" that were involved in physical land creation and natural forces (Regis, possibly?) while the elves became the spirit like the books in Canalave Library say.
This is one interpretation of the supreme One
and his hand is sort of beginning to look like Arceus to me now.This is going to be an absurdly long post. Oh well. 