The latest chapter of One Piece manga featured Straw Hat Pirates vice-captain Roronoa Zoro successfully taking down Beast Pirates headliner Scratchmen Apoo. Zoro and other members of their alliance went after Apoo with the goal of getting the antidote for the virus that Beast Pirates All-Star Queen the Plague created.
At first, Pirate Hunter was having a hard time catching Apoo. However, he became more determined to defeat him and obtain the antidote after he saw Kiku's arm falling from the sky. When he eliminated the headliner, Zoro told everyone at the banquet hall that he would be targeting the "strongest in the world" next. He was referring to Beast Pirates captain and Emperor Kaido, who is currently fighting the Nine Red Scabbards -- Kinemon, Denjiro, Raizo, Kiku, Izo, Kawamatsu the Kappa, Ashura Doji, Nekomamushi, and Inuarashi -- at the dome.
Before he left the banquet hall, he handed the antidote to Straw Hat Pirates doctor Tony Tony Chopper. Though he's also infected by the virus, Chopper confidently told Pirate Hunter that he wouldn't die. He revealed that he already figured out the composition of the virus and said that he's planning to cure everyone, whether they are their friends or enemies.
After learning about his plan, Queen tried to eliminate Chopper by attacking him using his machine gun. Luckily, Zoro was still there to defend Chopper. Zoro unleashed a powerful slash that destroyed Queen's weapon and told him that he's no longer interested in playing their game.
From the time he saw Kiku's severed arm, Zoro knew that there was something wrong on the rooftop. However, even if he wanted to go there as quickly as possible, he was fully aware that it wouldn't be easy. Aside from Queen, he would also need to deal with another Calamity -- Beast Pirates All-Star King the Wildfire -- whose main goal is to prevent enemies from reaching Emperor Kaido.
The easiest path to the dome is to follow the route that Big Mom Pirates captain and Emperor Charlotte Linlin took, but unlike the lady Yonko, Zoro couldn't fly. Luckily, another powerful ally arrived to give Zoro a ride - former Whitebeard Pirates first-division commander Marco the Phoenix.
After a brief altercation with Emperor Big Mom and Charlotte Perospero, Marco headed straight to the banquet hall to help the Straw Hat Pirates. In his phoenix form, Marco could easily take Zoro to Emperor Kaido without the need to deal with Queen or King. Monkey D. Luffy may be the one who's expected to defeat the strongest creature in the world, but Pirate Hunter would still be a huge help, especially now that he possesses Enma -- the sword that the late Lord Kozuki Oden used to pierce Emperor Kaido's tough body.