Emperor Big Mom and Emperor Kaido are two of the strongest characters in the world of One Piece. They consider each other as mortal rivals in finding the greatest treasure, One Piece, and earning the title as the next Pirate King. However, the latest chapter of One Piece revealed that Emperor Big Mom and Emperor Kaido are former allies.
In the ongoing One Piece Wano Arc, both Emperors of the Sea made an appearance. Emperor Kaido is currently the ruler of Wano Country, while Emperor Big Mom intentionally headed to Wano Country to kill Monkey D. Luffy and all the members of the Strawhat Pirates. When Emperor Big Mom and her crew tried to enter Wano Country, they were attacked by Beast Pirates All-Star King the Plague, resulting in their ship, the Queen Mama Chanter, to fall into the sea.
One Piece Chapter 934 confirmed that Emperor Big Mom and most of the members of the Big Mom Pirates are still alive, but Charlotte Linlin is separated from her crew. In the latest chapter of One Piece, Charlotte Perospero, Charlotte Smoothie, Charlotte Mont-d’Or, and Charlotte Daifuku were having discussions regarding their plan to infiltrate Wano Country and find Emperor Big Mom.
With her Vivre Card remaining intact, the Big Mom Pirates know that their captain is not yet dead, but they are worried that she’s already been captured by Emperor Kaido and the Beast Pirates. This is when Mont-d’Or revealed that Emperor Big Mom and Emperor Kaido were “allies in the past.”
— ONE PIECE.com(ワンピース) (@OPcom_info) February 27, 2019
Fans have been creating speculations about Emperor Kaido and Emperor Big Mom ever since they contacted each other during the One Piece Reverie Arc. Emperor Big Mom urged Emperor Kaido to team up with him in taking down Luffy and the Strawhat Pirates. Emperor Kaido refused, but Emperor Big Mom reminded him that he has a huge debt on her.
Before they formed their own pirate crew and became Emperors of the Sea, Emperor Big Mom and Emperor Kaido were believed to be former members of the Rocks, a legendary pirate group who was prominent before the late Pirate King Gol D. Roger came into power. The members of the Rocks have separated after losing their leader, but “Black Cage” Hina revealed in one of the chapters of One Piece Reverie Arc that their power is still growing. Monkey D. Garp, who became the “Hero of the Marines” after clashing with the Rocks, said that there is only a minimal possibility that the legendary pirate group will come back, but they will be a “real threat” when it happens.