The Carbonic Acid King Arc is the fourteenth filler arc and the fifth filler arc after the timeskip. It ties into the movie One Piece Stampede.
Summary
Some time before the Pirates Expo, Cidre is invited to attend, lured by Douglas Bullet's arrival. At the same time, his guild is in the process of attacking the Thousand Sunny. After escaping an attack from the guild, the Straw Hat Pirates cola supply runs low, and they sail to a nearby island for repairs and supply. While there, Luffy has a run in with the guild again and after being blown away, he meets Boa Hancock at the island's bath house. Despite her being a Warlord of the Sea, the guild decides to take out Hancock as well, and pin the blame on Luffy. The two then head toward the factory used for the guild's base and face off against Cidre.Tropes
- Continuity Nod: When Cidre's guild show up at the bath house to take out Luffy and Hancock, the former remembers the latter being very secretive about the Slave Brand on her back and, since he fell onto her while she was taking a bath, initially wants her to let him handle Cidre's guild on his own so that they won't see it.
- Continuity Snarl: As with the Silver Mine Arc, this arc is difficult to place in official canon. For starters, this mini-arc aired in the middle of the Land of Wano Arc.
- Like with Stampede itself, the mini-arc doesn't fit before the Wano arc despite Luffy having the same status as the unofficial "fifth Emperor" that he had going into it, because the whole nine-person crew is together in the arc, but in the series proper, the crew was split in half since midway through Dressrosa and only reunited again at Wano.
- It doesn't work for these episodes or Stampede to take place after Wano, either, as there are a few snippets that would be out of place: the fact that Boa Hancock is still a Warlord when her status was revoked during the Wano arc, Jinbe isn't seen despite the fact that he finally united with the rest of the crew during Wano, and Luffy had Awakened his Devil Fruit, which would've made the battle with Bullet much smoother.
- Curb-Stomp Battle: Hancock defeats Ginger and Guarana with little trouble. Neither of them even lands a single hit on her.
- Fanservice: The Carbonation Island has hot springs and, not surprisingly, when Hancock enters the story she's found bathing in one when Luffy is flushed into her spring after falling into a drain.
- Frame-Up: What Cidre plans to do to Luffy. When he decides to kill Hancock along with Luffy, since Hancock is a Warlord and this would get them into trouble with the World Government, he states that they'll claim Luffy killed Hancock and they killed him afterwards. Unfortunately for Cidre and his guild, they are far too weak to even come close to killing either one.
- Guest-Star Party Member: Hancock and her sisters, Sandersonia and Marigold, along with Nyon.
- Making a Splash: Cidre's Army all used a form of carbonated water as their main weapons. Cidre used it to power his rig which allows him to spin his fist to drill like proportions. Ginger uses them for high powered blasts from his canon and Guarana sprays hers around via nozzles to wield the high pressure water as "swords" of sorts. Likewise they can all fly via barrels strapped to their backs that spray out the water as a jetpack of sorts. And their troops uses high pressure wrist guns as their standard weapon.
- Prequel: A lead in for One Piece Stampede. Festa sent Cidre an invitation to the Pirate Festival that Luffy finds and leads the crew to Delta Island, the setting of the movie.
- Punched Across the Room: If nothing else, Cidre does have some strength on him. Once he get his rig and uses it on Luffy, it knocks him through three rooms of the factory.
- Taken for Granite: Ginger and Guarana end up turned to stone via a single kick from Hancock.
- Thanks for the Mammary: Luffy meets Hancock by falling directly into her chest.
- Theme Naming: Cidre's Army is based of course on various ingredients used for drinks. Cidre is cider, Ginger is pretty obvious and Guarana is a type of plant used in ale. Add to the fact they all used carbonated water as their main weapons and there you go.
- Trapped in Villainy: Save for his commanders, Cidre's army are actually residents of the carbonation island whom Cidre forced into working for him. During their fight against Zoro and Sanji, they quickly give up and plead for them to save them.
- Underestimating Badassery: Par for the course for a One Piece villain, but you think Cidre would take more care against someone whom the government considers dangerous enough to give him a bounty of 1,500,000,000 Beri and even moreso when he targets Hancock as well, a Warlord of the Sea. But no, he figures his specialized rig and high pressured carbonated water will be more then enough to deal with them... and easily ends up knocked out in the ensuring fight when he gives Luffy time to recover while he's gloating. Likewise his commanders are swiftly taken down by Hancock herself without even scoring a hit on her.
- Wingding Eyes: Hancock, ironically enough, gets this around Luffy, of course.
