WARNING: The following contains spoilers for One Piece Chapter #1018 by Eiichiro Oda, Stephen Paul and Vanessa Satone, available in English now from Viz Media.
The world of One Piece is full of strange and marvelous items that allow their users to pull off astounding feats. But not all weapons get equal attention within the fandom, with many being totally overlooked. One such example is the Climate Baton belonging to Nami. However, with its latest upgrade in One Piece Chapter #1018, it's going to be noticed by a lot more people.
The Climate Baton started out as a simple three-piece bo staff that Nami kept in case she needed to defend herself, though she usually relied on her knowledge of weather systems to keep her safe when trouble erupted. However, Nami realized how weak she was compared with the rest of the crew and that she couldn't rely on the others to protect her forever. So, she asked Usopp to create a powerful weapon that she could use to defend herself and support the team.
Understanding Nami's worries, Usopp took the bo staff and upgraded it, turning it into the Climate Baton. While still superficially a bo staff, the Climate Baton became augmented with technology that allows each part of the staff to create bubbles with different properties. One part produces heated air, one generates cool air, and the final part emits electrified air. By cleverly merging these together, Nami can create many different effects. This includes combining hot and cold air to make tornadoes, using all three sticks to create thunderclouds and disorienting mirages.
Usopp later performed another upgrade, turning it into the Perfected Climate Baton and further tailoring it to mesh with Nami's fighting style. This version of the staff allows her to pull off massively upgraded versions of the Climate Baton's moves, including more devastating thunderclouds. But this isn't the end of the Baton's upgrades in One Piece.
During her stay in Weatheria, Nami improved the staff with local technology, creating the Sorcery Climate Baton which allowed her to use even more powerful weather abilities. She then gave the weapon to Usopp, who used Pop Greens to enhance it even further -- including a stylish new orange paint job.
But the latest upgrade in Chapter #1018 is poised to be its most impressive one yet. The Climate Baton is now home to Zeus, a cloud homie who was aligned with Big Mom. During the escape from Totto Land, the Straw Hats took Zeus as a hostage. He was later recovered by Big Mom in Wano Country, but their relationship started to fray, leading to Big Mom eventually betraying and replacing Zeus with another homie due to his failures.
She planned to have this new homie, Hera, eat Zeus and consume his soul. When he resisted, Big Mom ripped out Zeus' soul, hoping to make it easier for Hera. Then at the last moment, Nami stepped in to help Zeus fight off the attack. Hera tried to devour both Zeus and the Climate Baton but failed, and due to Zeus' soul being free, it merged with the Climate Baton, turning it into a sentient weapon.
As Zeus is made from a fragment of Big Mom's soul, he is much stronger than other homies in One Piece. His status as a cloud means he can produce rain and massively damaging lightning bolts. He can also improve his strength by consuming other clouds and weather phenomena. When combining these powers with the Climate Baton's ability to create weather and Nami's knowledge of weather systems, the Baton is now a dramatically more powerful and versatile weapon. Zeus' sentience also allows the Climate Baton to operate semi-autonomously, allowing for even more unusual attacks.
The Climate Baton is a fascinating weapon as it represents Nami's continued development as a character. It shows how her knowledge of the weather as well as her desire to help others has affected her journey in One Piece. On top of this, the weapon allows the writers to come up with some unique and creative combat sequences, and the addition of Zeus means Nami's combat can become even more versatile in the future.