Many things tbh:
- Urouge time
- Big Tree leads to Giant and Sky Island lore (because of Urouge time)
- Big Tree is actually Treasure Tree Adam
- Because its Adam, the Underworld partially resides in Elbaf, taking Adam Wood (how Franky got wood for Sunny)
- Adam and Sunlight Tree Eve on Red Line/Mariejoa form High West (a series of sky islands that head back towards Skypiea)
- Lunarian's chased from Mariejoa now reside in Elbaf with Giants.
- God Elbaf is an actual person, like Nika, possibly a Lunarian
- Scopper is waiting for the crew in Elbaf
- Scopper will know where the Burned Scar Man is located (either Elbaf or somewhere else), possibly tied to Rocks (yay more God Valley).
- Level 6 Escapees may be tied to Burned Scar Man, just a guess.
- Stussy will join (hopefully) the Elbaf ship and be our guide to Rocks and Underworld lore too.
- Warland is a series of Islands, Elbaf is just at the center due to the Giant tree. The tree's roots are connected to all the islands (you can see tendrils of the tree going beyond the horizon in some scenes)
- And yes, maybe some BM involvement (or Rocks & cloning altogether)
All i got currently. I think Elbaf is meant to be the last bastion of Oda's ideas before we head to the endgame war. And if not...then a lot of this stuff goes unanswered.