#10 – LUCKY ROO
Lucky Roo is one of Yonko Shanks’ most important men. He’s the first person to kill someone both in the anime and the manga, by shooting a mountain bandit in the head at point blank range.
During Romance Dawn, we see one of Higuma’s men pointing a gun at Shanks’ head, then after Shanks warns him suddenly Lucky Roo appears and shoots him. Now here’s the question, how can a big man like that go there that quickly without being noticed? It is likely that he is based on Lucky Luke (a fictional cowboy -gunfighter- from the “Lucky Luke” Franco-Belgian comic book) that is known as “The man who shoots faster than his shadow”.
Lucky Roo he’s supposed to be a Haki master or, anyway, a master in something different; in particular, many speculated that he uses a technique called “Life Return”. In this case, Lucky Roo eats so much because he is storing energy for a battle. Life Return gives him the ability to control his body; this can be used to turn fat into muscle, or just turn fat into energy.
#9 – BENN BECKMAN
Benn Beckman has the highest IQ of anyone in the East Blue. Across his voyages he’s learned a lot of experience, with an incredibly advanced intellect and great thinking capabilities.
When the Red Hair Pirates arrived at Marineford to stop the war, Beckman was able to climb on to a Marine ship’s mast and sit on it, all the while pointing his flintlock at Kizaru, without the latter noticing. Admiral Kizaru chose not to fight him, even though he had just fought the First Commander of Whitebeard’s crew and Whitebeard himself.
According to “One Piece: Vivre Card Databook” Benn Beckman is almost as strong as Shanks! His card says that Benn is incredible powerful in terms of physical combat. The card even says that “Comparable to Red Hair’s, this man’s existence is feared by even the powerful warriors of the New World!!”
#8 – KUZAN
Kuzan is a former Marine admiral. He was nominated by Sengoku for the position of fleet admiral but after losing the position to Sakazuki, he resigned from the Marines and affiliated himself with the Blackbeard Pirates.
Kuzan has the powers of the Hie Hie no Mi, a Logia Devil Fruit that allows him to control, create, and become ice. In battle, he uses his ice powers to disable and immobilize enemies, freezing their bodies solid just by touching them, and threatening to shatter their fragile forms. This fruit is so powerful that his usage of it during his ten day battle with Akainu permanently changed the weather on one side of Punk Hazard, turning that side into a frozen wasteland.
Kuzan was considered to be a massive asset to the Marines, and his departure left a negative impact to their military strength. This was confirmed by the Gorosei calling him an ‘enormous power’ while discussing his affiliation with the Blackbeard Pirates, to the point of being visibly distraught while doing so.
#7 – SILVERS RAYLEIGH
Silvers Rayleigh, also known as the “Dark King”, is the former first mate of the Roger Pirates, known as the “Right Hand of the Pirate King.
Rayleigh is extremely powerful, easily one of the strongest characters introduced.
He could intercept Kizaru’s attack when the Admiral was about to kill Roronoa Zoro without Kizaru noticing, and also managed to keep up with his light enhanced speed.
Rayleigh is one of very few people who can use all 3 types of Haki: Busoshoku Haki, Kenbunshoku Haki and Haoshoku Haki.
Rayleigh infact has shown to possess great mastery of Haki, and made use of all three types while teaching Luffy about them, and training him in the basics. He can utilize an advanced application of Busoshoku which enables him to emit his Haki a short distance without a medium. Rayleigh is also able to use a high-grade version of this technique, where he can channel his Haki into his opponent, letting him destroy them from the inside out, which he first used to destroy Camie’s collar.
#6 – DRACULE MIHAWK
Mihawk is the current holder of the title, “Greatest Swordsman in the World”.
Part of Mihawk’s reputation as the most powerful master swordsman in the world is also due to his tremendous superhuman physical power and fortitude which supplements his mastery of swordsmanship. He possesses an immense amount of skill in battle and has exceptional eyesight.
The fact that Mihawk used to be a rival of one of the Yonko implies that Mihawk might be one of the strongest characters in the series. Infact he has been known to have frequently fought with Shanks when they were younger. Their battles were said to shake the whole of the Grand Line and Mihawk often sought Shanks out for duels. However, Mihawk lost interest in him after Shanks lost his left arm.