this is my first theory on this site. I also hope nobody has made this already, since I didn’t check.
So my theory regards the 3 things from the title.
DF abilities, Haki and seastone.
There is something that has always bothered me. Not bothered in the sense that I didn’t like it, just in the “how does it work?” kinda way.
Smoker has a jute with a seastone and he can transform into smoke completely, including the seastone. But DF Abilities and seastone are conterparts. Seastone a negate the effect of DFA.
Haki is something that also is a counter force to DFA, yet DF users can combine them with their Haki.
And in Udon Luffy stated he couldn’t use Haki as long as he had the seastone handcuffs on.
So seastones also suppress tha Haki of a user.
And it takes a lot more seastone(or purer) for stronger people. For example doffy was chained with quite a few seastone chains and big mom even more. And it didn’t even seem to weaken her. Although we know the chains in wann are 100% pure.
So here is my theory.
The 3 abilities, let’s call them that, are directly opposing each other. But it’s possible to also coexist. For example smoker kan imbued his Haki in its jute. Because he isn’t directly touching it. And he can turn it into smoke. So we also know it’s possible to turn a blade into e black blade through Haki.
I think seastones are stones with the Haki of someone(possible Joey boy), who imbued them with his Haki and its will to deactivate DFA and the will of others. But if your will(Haki) becomes stronger than that it can’t do it anymore. And it it’s possible that in the future Luffy can use his conquers Haki to deactivate the abilities of DFU, just like seastones do. Obviously the stronger the opponent, the harder it will be. I also think the this three things Haki, DFU and seastone have the same origin, the ancient kingdom.
What do you guys think?