In chapter 906 we are introduced to what seems to be the “National Treasure” that Doflamingo has referenced in the past and in chapter 906 itself.
What we are to understand from the panel is very vague however.
We see a lone figure carrying Luffy’s new wanted poster opens the door to a freezing vault. Stepping inside, the vault is revealed to contain a single object: a massive straw hat the size of the figure.
All this made me think of the the cover page for the chapter 470
If you see the image upside down you can see that in the wall there is a giant straw hat and those soldiers(?) have straw hats too, you can also see how they are reviving someone.
My theory is that the Marines/Celestial Dragons want to dismantle the Sichibukai and revive the seven greatest pirates (as you can see there are 7 altars).
Is it possible? What do you guys think?
*Theory by Kire2512