I was re-reading Big Mom's Elbaf flashback the other day and something struck me. The Solstice festival was one of those things that I didn't really think about for the longest time, but this time I realised that the fact that they celebrate it and keep talking about appreciating the sun means that it is very important for their culture. And that got me thinking how we already know the moon is important in the story (most notably because of Enel's space endeavours). So what if it's like:
Zou/Wano - arc of the Moon
(Kozuki symbol being a reverse crescent moon; the Minks' Sulong forms)Elbaf - arc of the Sun
(Solstice, ???)How this would actually come into play in the story, I wouldn't know. I just find it fascinating how these 2 arcs in the New World that we've been anticipating for a long time appear to have opposing symbols they attach significance to. We may not see that much of the sun besides some symbolism and imagery, but it's a fun thought experiment.
I know this is an old comment, but I figure I might as well reply to it. Anyway, the giants of Elbaf are loosely based on the Vikings. In the Viking myth of Ragnarok, the wolf Fenrir devours the sun and the moon (I believe some versions of the myth say that Fenrir's children will devour the sun and moon). I have a suspicion that Blackbeard or one of the three weapons is going to block out or eat the light of the sun, moon, or both and cause havoc. I think this would fit well with the theories that the Red Line represents Jörmungandr.
The Wano and Elbaf arcs will probably shed some light on how Devil Fruits came into existence or grow (from a World Tree and/or the Adam and Eve trees?) and how seastone is made. Maybe they are priming us for the 'Ragnarok' of the One Piece world or how the One Piece world has previously dealt with Ragnarok.