Warning! Major spoilers for One Piece Chapter 957 below!
One Piece's manga has been steadily building to a major war breaking out in Wano Country, but before this battle has kicked into gear there appears to already be massive ramifications going through the world. Now that the manga has begun to reveal the aftermath of the Reverie mini-arc, there seems to be one major reveal after another with each new chapter. But Chapter 957 shakes things up even more by revealing a major piece of the series lore and opening the whole thing up further than fans had ever expected.
Chapter 957 of the series sees the military prepare to take on the Four Emperors, and during this we got their bounties, a surprising connection in their past, how Garp became a hero, a mysterious powerful pirate who was of the same level of Gol D. Roger and much more.
New Admiral Sakazuki is preparing the Marines for all of the major developments currently going down. Not only do they now have to capture the dissolved Seven Warlords, but they have to deal with Big Mom and Kaido's new alliance at Wano. Right now they're just gathering intel and mention that Kaido and Big Mom, along with Whitebeard, and many other legendary pirates were a part of a crew dubbed "Rocks" when they were younger.
This crew had a captain who had near the same level of infamy and power as Gol D. Roger, and they eventually grew so strong and violent that they were wiped out by the government. As part of a massive conspiracy, the world government wiped out this entire crew at this island named "God Valley." It's here where Garp earned his title of hero of the Navy, but the reason he never talks about the event itself is that he had to protect the Celestial Dragons and their slaves from the Rocks Pirates.
Working together with Gol D. Roger, Garp was able to break up this group, and soon God Valley disappeared off the face of the map. The Captain of this dangerous group was Roger's first major foe, named Rocks D. Xebec, and only legends remain. Bringing it to the present day, the Navy revealed the massive bounties for the four current emperors along with the deceased Whitebeard and Gol D. Roger for the sake of comparison.
This was all done to further emphasize just how bad Big Mom teaming with Kaido is going to make things for the Navy, and this is all made even worse when Wano appears to be at the center of it all. It's revealed that Kozuki Oden, the mysterious Wano daimyo who Luffy and the others are fighting for the honor of, was a member of Gol D. Roger's crew too. It's clear that Wano is the epicenter of much of the world's powerful figures, and these reveals only tease an intense future battle to come.
Eiichiro Oda's One Piece first began serialization in Shueisha's Weekly Shonen Jump in 1997. It has since been collected into over 80 volumes, and has been a critical and commercial success worldwide with many of the volumes breaking printing records in Japan. The manga has even set a Guinness World Record for the most copies published for the same comic book by a single author, and is the best-selling manga series worldwide with over 430 million copies sold. The series still ranked number one in manga sales in 2018, which surprised fans of major new entries.