Looks like he wasn’t just a swordsman…
In the Wano Country arc in One Piece, we have seen a series of important reveals of the most outstanding characters. One of them has been Kozuki Oden, the legendary swordsman of this nation (with clear references to feudal Japan). Known for his supernatural fighting abilities, that of his own creator confirms that Kozuki Oden’s most important “power” was another unique ability. This article will contain spoilers, so if you don’t want to miss them, you can watch the manga chapter by chapter at MangaPlus by Shueisha.
After his power started to grow, he generated the desire to leave Wano and see the world, what he did upon joining Whitebeard’s pirate crew a few years later. As a member of the crew, Oden further developed his already incredible fighting skills. In fact, aside from Luffy, Oden was the only person known to have hurt Kaido at his best. Consequently, it would be reasonable for fans to believe that when Gol D. Roger asked Whitebeard to “lend” Oden’s services for a year, it was because he wanted to make use of his fighting skills. In fact, having Oden’s help on a journey was almost like having Whitebeard himself on the journey.

Kozuki Oden was the previous user of Enma, who was able to master his full power as a swordsman.
However, the reality was a bit more different, Gol D. Roger didn’t need Oden’s fighting skills, he was looking to use his “other skills”. Indeed, in addition to their own strength as warriors, the crew Roger commanded could take on the best with intelligence and creativity. As made clear in Road to Laugh Tale, what really made Oden was so vital were his skills as a translator.
These abilities may be more reminiscent of Nico Robin than Yamato or Zoro or any other swordsman. The reason why Roger begged Whitebeard to release Oden was perhaps the only aspect of his family duty in Wano that he was willing to learn.namely the Kozuki clan’s ability to read and write the secret language inscribed in the mysterious Poneglyphs.
The Kozuki Clan was responsible for inscribing the stones hundreds of years ago.. As a result, the ability to understand language was passed down to each successive generation all the way to the mighty Oden in One Piece. At this point, Roger knew that he needed someone who could read stones and was delighted to meet Oden through his confrontation with Whitebeard. Roger knew that Oden was the key to continuing the journey to Laugh Tale.
Kozuki Oden’s true power in One Piece was his ability to write and read in the mysterious language of the Ponelyphs.
Naturally, Roger also made use of Kozuki Oden’s martial skills., eventually becoming one of the toughest fighters and most reliable warriors in the crew. However, the first and foremost benefit of it to Roger was his ability to translate Poneglyphs, without which Roger would never have had a chance at obtaining One Piece.
In a One Piece world filled with super-powered characters, Kozuki Oden stands out as not only one of the greatest warriors in the Four Seas, but also one whose greatness isn’t based on eating a devil fruit. However, despite his success on the battlefield, his most important skill had nothing to do with his martial prowess.

Oden is one of the most powerful characters in Wano Country in One Piece.
Born to Lord Kozuki Sukiyaki, the leader of Wano Country, Oden’s life was set. All he had to do was learn the family “business” and stay out of trouble, and in due course he would replace his father as leader. However, Oden had other plans. At first, he showed a deep disinterest in following the family tradition. Instead, he preferred partying, fighting, and chasing women, three skills in which he showed great expertise. Naturally, this led to him getting into trouble with the law and being exiled by his father to Kuri, the wild and lawless outer region of Wano. It was in Kuri that Oden began to mature and decided that he wanted to do something with his life. His first step towards reform began with bringing order to Kuri. And from there his knowledge and powers became a great strength in One Piece.