Link: https://onepiece.fandom.com/wiki/Will_of_D.
The "Will of D." is a mystery surrounding some people who have the initial "D." in their names.
The initial was first pointed out in Oda's SBS questions and answers corner, when he was asked what the D. in Luffy's name stood for. Oda just replied to read it as a D. for now and that he would reveal the truth behind it in time. This was the first time the D. in Luffy's name was brought up, as well as Oda's first hint toward a bigger mystery.
Related questions
Devil Fruits came from the family of D, who are the natural enemy of Gods. So stands for devil?
The origin of devil fruits are not yet explained. History was more technologically advanced back in the day before what ever conflict (s). Joining them to the 'family of D' makes sense.
Donquixote Rosinate:
family of D.
misbehavior => eaten up by D. (Like Hell).
Natural Enemy of God -> Devil.
The behavior of the people with the will of D is rather disruptive and chaotic. More CE than LE but I'll take it. Good vs Evil defined by the ruling class.
So I've bumped up Devil. It's less pretty but I think it has the most backing it.
I hate seeing any theory mention anything about the “Will of D.” because I keep thinking anything that starts with a D is a valid theory.
Added “drums” because of “Drums of Liberation,” the cymbals in chapter 1109, how the musical notation for cymbals is an O with an X through it (which is also represented in the logo with the bones representing the X), and how his new move is “Dawn Cymbal.”
Never even thought of it until I read a theory about it, had to create the answer.
@strutheo Where going to gather up all our dreams and set out in search of something to find - One Piece