First of all, thanks to Marco Polo for bringing up this theory in another thread. I hadn't read the latest chapter of One Piece yet when he did, but in light of new information in it, I decided to make this theory. Marco, I hope you read this and let me know of your opinion in either theory thread.
Rather than a stand-alone theory, this is a short continuation of one of my old theories in this forum. I didn't want to go back and edit it because it's already long enough by itself and I'd ideally like it to be left untouched as the "original". I'll make a summary of the points I'll be basing this theory on, so you don't necessarily have to read the original one, but for anyone who wants to see the full picture, here it is:
So, in my original theory, I point out the possibility of haoshoku haki, or to be more precise a person's "will / soul" (so their haki, and in particular haoshoku), is the absolute prerequisite of "becoming" Joy Boy. Yes, I've stood for the opinion of Joy Boy being a "title" rather than a person and Kaido has most recently validated my at-the-time crazy sounding opinion:
If you've read my original theory, there's not much to say now but for those who haven't, I basically suggest that one can become Joy Boy when their soul's / haki's "character" is similar to the original Joy Boy's. This goes along the lines with the "inherited will" concept I strongly support in other theories as well and I believe it's the reason why no one else has managed to become Joy Boy. Because ideally so, if you don't somehow cheat your way through it, it's not the strength or technique of one's haoshoku haki that's essential but its "character". And I believe said character to be similar to Luffy's ability to "make anyone he meets his friends", including the 3 ancient weapons like I suggest in my original theory.
I've been of the opinion that haoshoku haki, and more importantly its advanced version, will have a huge impact on the story by proving an essential way to realize the concept of "inherited will". I elaborate slightly more about it in another theory of mine for anyone who's interested:
This was a theory made by yours truly, Yuuzume. :