The Wano arc was the longest One Piece story to date. It follows the cinematic conclusion of the Four Emperors' saga, Luffy's recognition as a serious naval force, and much of the history behind legendary characters like Roger and Ace. Further, villains Kaido and Big Mom were finally confronted at the heights of their respective power.
As one of the most hotly controversial arcs yet, there are many ways that Wano changed everything. By identifying them, it becomes easier to obtain an understanding of its influence on the narrative as a whole and whether or not it was ultimately positive.
10 Advanced Armament Haki Was Introduced
Since Kaido was a more impervious opponent than anything Luffy faced so far, he needed a new way of damaging him. After being imprisoned in Udon, he came across Hyogoro and was taught advanced armament haki.
Instead of dealing direct damage to the target, advanced armament haki funnels the user's spiritual energy directly inside them. As a result, it's an amazing weapon for bypassing Kaido's thick skin and muscles to deal substantial damage. Luffy also used it in order to remove his chains and liberate the prisoners of Udon.
9 Ace's Backstory Was Further Clarified
Despite being considered a staple character of the series, fans had only received a limited idea of Ace's personality up until Wano. He only made a brief appearance at Alabasta before the fight at Marineford, leaving many feeling unfulfilled about the man he was.
Although Luffy's backstory clarified Ace well, his time with the Whitebeard pirates was further built upon through Yamato's flashbacks. They explained what he was like and how he inspired their insatiable lust for freedom. Considering that Yamato has since aided Luffy, Ace continues to look after his brother from beyond the grave.
8 Zoro Replaced His Swords
Having won his blade from a battle against Ryuma at Thriller Bark, Zoro grew fond of it and initially refused Hiyori's efforts to take it back. However, he was compensated with one of Oden's weapons, Enma, which had been forged by the finest weapon smiths in Wano.
Considering that it was also responsible for cutting Kaido without advanced armament haki, Zoro was given one of the best weapons in the world. It will be extremely useful to him as the Straw Hats embark on their final voyage.
7 Oden Clarified Roger's Story
Considering that Laugh Tale couldn't have been found without the poneglyphs, it was initially never explained how Roger first got there. Fortunately, the Wano arc helped to elucidate one of the series' greatest mysteries by introducing Kozuki Oden.
His insatiable lust for adventure compelled him to assist the Pirate King in his quest, and together, they eventually found the One Piece. Oden was also instrumental in the formation of Wano as it is today, training the Scabbards that have helped Luffy since Punk Hazard. Further, he set a standard for the caliber of strength that would be needed to defeat Kaido.
6 Marco Helped The Heroes In Wano
After the Payback War, the fate of the Whitebeard pirates were largely unknown. With Big Mom and Kaido's forces beginning to unite, it started to seem as if the villainous alliance would crush all dissenters. Luckily, Marco the Phoenix intervened on the heroes' behalf and substantially delayed Big Mom's reinforcements.
This had a major implication for the rest of the series since it meant that even though Whitebeard's crew disbanded, the heroes would still have one of the most powerful emperor commanders in history to assist them.
5 Sanji's Raid Suit Debuted In Wano
Considering how late Sanji received his Raid Suit from Germa 66, it never had a chance to properly debut in Whole Cake Island. Shortly after Wano began, however, its full potential was revealed. In addition to increasing his durability and speed significantly, the raid suit allowed Sanji to turn completely invisible.
This helped him stay a relevant competitor to Zoro, especially given the swordsman's recent upgrade in weaponry. Further, Sanji's invisibility renders him arguably the best stealth character out of the entire Straw Hat Pirates.
4 Jimbei Joined The Crew
Ever since Fish-Man Island, Jimbei promised that he would eventually join the Straw Hats as an official member. Unfortunately, he did not have an opportunity to make good on that promise until the operation on Whole Cake island since Big Mom had a stranglehold on his people.
Nonetheless, Jimbei pledged himself as the official helmsman for Luffy's crew shortly before the invasion of Onigashima began. This surprised and delighted the captain even if they did not have the opportunity to throw an official celebration in the fish-man's honor. Despite his unceremonious introduction, Jimbei proved invaluable to the crew's efforts.
3 The Extent Of The Artificial Devil Fruit Operations Were Revealed
The artificial Devil Fruit operations were a significant part of the New World saga. It began at Punk Hazard with Caesar Clown's S.M.I.L.E factories though expanded into Doflamingo's smuggling operations in Dressrosa. In Wano, audiences had an opportunity to understand the extent of Kaido's scheme.
A significant portion of his forces known as the "Gifters" received these Devil Fruits and became super soldiers. The emperor wasn't stockpiling strength idly – he intended to wage war against everyone using Wano as his new fortress.
2 Green Bull Was Properly Introduced
Although Green Bull was technically introduced in the Reverie arc, he made a more formal introduction in Wano. Hoping to enforce the World Government's wishes, he ravaged the land though was promptly waylaid.
Despite being defeated, Green Bull's presence gave audiences a taste of his power and an idea of the current composition of the three admirals. Between him, Kizaru, and Fujitora, the Straw Hats and Revolutionary Army will have no shortage of difficult opponents if they hope to overthrow the World Government once and for all.
1 Kaido & Big Mom Were Finally Defeated
Established as early as Thriller Bark, Big Mom and Kaido were defeated close to the same time during the raid on Onigashima. This had a staggering impact on the outside world, especially since it created a vacuum in the Four Emperors.
Despite playing a direct role in Big Mom's defeat, neither Law nor Kidd were considered to replace her.
Instead, Buggy unexpectedly seized the mantle, having grown to a position of prominence through his vast mercenary empire. Nonetheless, Luffy's direct victory over Kaido made his ascension much more straightforward, especially given his previous escapades in Whole Cake Island and Marineford.