Each of the Straw Hat Pirates has their own role and unique characteristics. Being superhumanly powerful like Zoro or Luffy isn't Nami's forte, which is a rare sight in One Piece. But in order to survive in the world wherein only the toughest tread, she has to compromise one way or another. Since One Piece is home to various powerful weapons, Nami also equipped herself with an ingenious item: the Climate Baton, or Clima-Tact.
Nami's main skills are thievery and navigation. She managed to get by fleeing and relying on her crewmates during the earlier arcs of the series. However, the moment the Straw Hats started to sail on the infamous seas of the Grand Line, making herself scarce during huge fights was no longer a viable option. She had to find a way to pull her own weight, so she approached Usopp and asked the crew's innovative sniper to make her a weapon that would suit her.
The Climate Baton (Clima-Tact)
The Clima-Tact first made its appearance when the Straw Hats arrived in Alubarna during the "Arabasta" arc. Usopp created it under Nami's request, and he modeled it after Nami's original bo staff -- with some extraordinary features. Each part of the baton had a button and pressing it would trigger the piece to create a bubble with a certain property. Connecting the pieces in a specific way would also trigger a specific effect. Since Usopp thought Nami wanted it for a different reason, most of the features were harmless parlor tricks.
While most of the Climate Baton's functions were nowhere near useful in battle, Usopp did install one battle-specific component: Tornado Tempo. Triggering this feature caused two clockwork doves to entangle the opponent and spin them. Once reaching a tremendous speed, the baton launched them and knocked them down. In addition to Tornado Tempo, Nami was able to maximize the Climate Baton's features with her intellect. She combined the different kinds of air bubbles and her navigator knowledge to manipulate the weather, allowing her to create mirages and even hit her opponents with lightning.
The Perfected Climate Baton (Perfect Clima-Tact)
During the "Skypiea" arc, Usopp got his hands on interesting new materials called dials. These dials are shell-like objects that possess unique properties. Using what was left of the dials after upgrading his slingshot, Usopp also upgraded Nami's Clima-Tact. He removed its useless features and enhanced its offensive abilities, especially the features relating to weather manipulation.
The device he came up with was visually similar to the old one, but the Perfect Climate Baton had a ball-like attachment at the end of each piece. However, the Perfect Climate Baton's attack was so strong that it became difficult to control, which also put her allies at risk.
Sorcery Climate Baton (Sorcery Clima-Tact)
Unlike the first two Climate Batons, Nami is the one who created the Sorcery Clima-Tact during her two-year training in Weatheria. She incorporated the knowledge she acquired during her stay and Weatheria's technology into the Climate Baton and expanded its uses outside battle. Nami was able to alter it so that she could use it for trivial matters like showering as well as let the Sea Clouds survive on the Blue Sea.
The Sorcery Climate Baton got a further upgrade when Nami finally met Usopp after the timeskip. This time, however, Franky also lent a hand. Both of them incorporated what they had accrued during their respective training to make a better weapon for Nami. The Sorcery Clima-Tact no longer needs to be separated as it can expand and contract at will, and it's fast enough to deal a considerable force upon impact. Additionally, the Sorcery Climate Baton's power increased even more when Nami tricked Zeus into serving her during the "Whole Cake Island" arc. Zeus possessed the Sorcery Clima-Tact and acquired full control over the baton, turning its shapeshifting and other abilities into a sentient threat.
Nami's Climate Baton has come a long way. Given that its current form is a Homie, it is hard to imagine that this will be its permanent form. Zeus will likely perish the moment Big Mom loses her power. As to how that will happen and what will come next, fans can only hope that the answers are provided in future updates of One Piece.
