With One Piece's Wano Country arc now over in both the manga and anime, most fans will now be aware of just how formidable Luffy has become. After his long-lasting duel with Kaido and his awakening with Gear 5, it is safe to say that Luffy stands among the series' strongest characters in both the old and new generations. Defeating Kaido is a feat that nobody in the world of One Piece has accomplished except Luffy, at least according to what has been said in the story so far.