God Valley. The island which was the battleground for the most epic battle in the verse so far. Monkey D. Garp and Gol D. Roger vs The Rocks Pirates.
Sengoku saiying something like ”All these powerful individuals gathered there? Just what was on that island??” seems pretty suspicious to me.
Cutting right to the chase, I think what was on that island was the final dragon egg. We know Dragons were a thing in the One Piece world. Ryuma slayed one as we know. Those weren’t people transformed into Dragons through Devil Fruits. Those were the legit ones.
The Obsession Of The Celestial Dragons With Dragons
They call themselves Dragons. That’s point one.
Their symbol is the hoof of a Dragon. That’s point two.
They made Vegapunk create artificial Dragons. That’s point three.
Even Vegapunk’s failed artificial Devil Fruit was the one of the Dragon. That’s point four.
Clearly the Celestial Dragons are obsessed with Dragons for some reason. That’s why I believe the Celestial Dragons were on God Valley. It housed the final Dragon egg. They gathered there to get possession of it.
Rocks D. Xebec, who wanted to take down the Government, somehow learnt of a lot of Celestial Dragons gathered in one spot, and thought of assassinating them all at once, but was pummelled by Roger and Garp.
The Oro Jackson
We’ve seen a giant egg on Roger’s ship time and time again. But we don’t have any explanation for what is it.
I think after the events of God Valley, Roger managed to take possession of the egg and took it with him on his voyages.
Headcanon
The Dragon might now be in Laugh Tale, and might be guarding the One Piece like Oda taking an inspiration from Lord Of The Rings. Remember Smaug and the Dwarves’ treasure ? Something like that. We have a Dragon guarding a treasure.
That’s all I’ve got. Hope you liked it.
*Theory letsgomina