Scopper Gaban, a former Roger Pirate, was one of Gol D. Roger's trusted crew members, wielding two axes in battle. His strength likely earned him a bounty exceeding a billion berri, and he showed his combat skills in clashes with the Whitebeard Pirates, including Oden.
Ben Beckman, a powerful pirate introduced early in the story, relies on Haki in battles, without a known Devil Fruit power. While his Haki abilities remain undisclosed, Eiichiro Oda is expected to explore and reveal his true powers in the future.
Edward Weevil is one of the strongest pirates in the One Piece world. He was a member of the Shichibukai after the fall of Donquixote Doflamingo but shortly afterward, lost it during the Reverie.
Mihawk, the World's Strongest Swordsman, wields the Kokuto sword "Yoru" and possesses exceptional Armament and Observation Haki. While his full swordsmanship skills remain unseen, he is considered one of the world's most powerful figures, close to the level of the Yonko in One Piece.
Rayleigh, Gol D. Roger's right-hand man and First Mate, displayed incredible Haki mastery and took on Kizaru without a Devil Fruit. In his prime, he was likely even more formidable, as evidenced by his encounter with Kizaru.
Ryuma, known as the "God of the Blade" in Wano, was one of the strongest non-Devil Fruit users in the One Piece world. His legendary dragon-slaying feats and formidable sword skills suggest he could rival swordsmen like Mihawk.
Oden, the Daimyo of Wano Country's Kuri region and rightful heir to the Shogun position, demonstrated immense power from a young age. By the age of 11, he had mastered both Ame no Habakiri and Enma, two of the strongest O Wazamono swords.
Red-Haired Shanks is one of the Yonko, which automatically makes him one of the four strongest One Piece characters alive currently. He is the captain of the Red Hair Pirates, leading which he has gained a bounty of 4,048,900,000 berries.
Garp, the "Hero of the Marines," is the strongest known Marine, famous for his Armament Haki. He could battle Gol D. Roger and, along with Roger, defeated Rocks D. Xebec. In his prime and even in old age, Garp is among the strongest characters in One Piece.
Gol D. Roger, the Pirate King, was the strongest One Piece character, with Garp and Whitebeard as his peers. He had advanced Haki abilities, held Whitebeard to a draw without a Devil Fruit, and wielded the sword Ace. Roger was an unmatched pirate.