With the recent Vivre Card release, it has been confirmed that Sengoku has knowledge about the Void Century and the history of those who bear the name of D.
As far as the World Government is concerned these are the darkest secrets of the World. So forbidden is this knowledge, that even the smallest chance of it leaking out warrants a full-on Buster Call!!
Here are all the characters who have knowledge of the Void Century and the Will of D.
1-Im (he/she possibly experienced the events in person)
Im’s existence is a secret to the rest of the world.
The full scope of Im’s abilities are unknown, but the fact that he/she sits on the Empty Throne, a seat whose occupant would be associated with sole authority of the entire world, and the fact that the Five Elders, who are publicly considered to be the highest authorities of the World Government bow before him/her and address him/her with a great honorific, would indicate that Im has the greatest known authority within the World Government.
The Five Elders are the highest-ranking Celestial Dragons and the heads of the World Government. They essentially rule the entire world, with the only individual of higher authority they answer to being the mysterious Im who sits on the Empty Throne.
They are the men who command the Marines and Cipher Pol, and the ones who made a pact with the Shichibukai, making them one of the main antagonist groups of the series.
So far, none of their names have been revealed and it is unknown how they became the leaders of the World Government or how long they have been ruling it.
Silvers Rayleigh, also known as the “Dark King”, is the former first mate of the Roger Pirates, known as the “Right Hand of the Pirate King”.
Sengoku the Buddha was the Fleet Admiral of the Marines before the timeskip, succeeding Kong and preceding Sakazuki.
Sometime during the timeskip, he became an Inspector General.
Kong is the World Government Commander-in-Chief. He was the Fleet Admiral of the Marines at the time of the Battle in Edd War twenty-seven years ago and at the time of Gol D. Roger’s execution twenty-four years ago.
6-Monkey D. Garp
Monkey D. Garp is a Marine vice admiral. He is the father of Monkey D. Dragon, the paternal grandfather of Monkey D. Luffy, and the adoptive grandfather of Portgas D. Ace.
He’s also a “Hero” of the Marines, and as such is known for cornering and fighting Gol D. Roger many times.
7-Monkey D. Dragon
Monkey D. Dragon is the infamous Supreme Commander of the Revolutionary Army who has been attempting to overthrow the World Government. He is the World Government’s greatest enemy, and is the most dangerous and most wanted man in the world.
Scopper Gaban was a former core crew member of the Roger Pirates. His current whereabouts and status are unknown.
“Red-Haired” Shanks is the captain of the Red Hair Pirates and a member of the Yonko that rule over the New World. He is also a former member of the legendary Roger Pirates, the only group to successfully conquer the Grand Line.
Dr. Vegapunk is the leading scientist in the employment of the Marines. His work includes discovering the secrets and uses of seastone, the secrets of how Devil Fruit powers work, the co-discovery of the Lineage Factor and its applications, and various other scientific achievements that are said to be at least 500 years ahead of current technology. He hails from the technologically advanced Karakuri Island. Vegapunk has yet to make a personal appearance in the storyline.
Other Characters who may know about Void Century: