So the only thing about the mural that bugs me is, why is it drawn like the winged dragon fighting the massive serpent? Like in the second world mural you can see all the allies of Nika together and clearly they’re all fighting the same threat; however, the way the dragon and serpent are drawn, opposing sides of the mural, and in midst of an attack seemingly clashing in the middle makes it look like they’re enemies.
Watch this video:
Long story short, Oda's actually been using two different "words" when he talks about Dragons in the original Japanese. He uses one kanji for "Western Dragons" like we saw on Punk Hazard and another kanji for "Eastern Dragons" like we saw with Kaido's Fruit. So, there are probably two different factions of dragons in this story. Possibly one aligned with the Land God and another aligned with the Sea God. "Fire" against "Water".
Or the Forest God given the Tree. Maybe each of the Gods have their own set of Dragons?
...Maybe? We'll see. A possibility to keep in mind, at least.
Although, I'll admit, the "Flaming Serpent" on the right side of the splash page does remind me of Ju Peter's Sandwom form a bit. I have to wonder if there's some connection, there.