First of all this is my opinion if you disagree i would love to hear your opinion. Second of all I only chose characters who have been seen in combat or have combat history. For the list : 1. Kaido: He is called the strongest beast, he can’t be killed and probably is in his prime. We will have to enter the Wano arc to trully know his power but probably he is the strongest at the moment 2. Blackbeard: He is strong, he injured Shanks in a fight and he said he wasn’t going easy against him. He looked “weak” fighting against Ace, but remember, Ace was a Yonkou commander and he defeated him in a fight that seemed to last less than 15 minutes and resisted Ace’s strongest attacks and Blackbeard didn’t even try to avoid those attacks. He is a mistery and I hope we see more of him at the near future. He also has the “strongest” devil fruit the Yami Yami no mi and the most destructive devil fruit the Gura Gura no mi. Until now, he is the only person in One Piece who has 2 devil fruits. 3. Shanks: He is a Yonkou, was respected by Whitebeard and when he arrived at Marineford he stopped the war, not because he is the strongest, but because he could tilt the balance. At the moment, he has shown the strongest King’s Haki. 4. Akainu: Not everyone thinks he is at Yonkou level, but he is. He fought one on one with ' The Strongest Man in the World " Whitebeard and managed to critically injure him and after taking that big hit from Whitebeard, he stood up as if nothing happen. 5. Rayleigh: He was Gol D Roger right hand, he is not on his prime but with ease he stopped Borsalino, yes neither of them were fighting at his full but when he did that, Kizaru knew he f**ed up. 6. Big Mom: She is not the strongest because she is not on his prime, but my god she still is a tank. With her power she can fight at sea without a ship and destroy anything at her path. Just imagine her power at her prime, I think she was the strongest, and that’s why Roger didn’t fight with her, because he knew he couldn’t defeat her, remember, the pirate king is not the strongest because he/she could defeat everyone, the pirate king is the one who gets to Raftel, that’s why Big Mom has never been the pirate King (queen), or at least that’s what Oda made me understand 7. Kuzan: He fought Akainu for 10 days and lost, but that feat is just huge. The longest fight we have seen till now was Luffy vs Cracker and it only lasted that much because Luffy was eating. Just imagine how much you must lose after a fight for 10 days if you don’t control your haki as needed. He is at 7th place because he lost one of his legs at the fight and even he uses his devil fruit to have a “prothesis” I think he is not that strong because of that. 8. Mihawk: He is called the best swordman and was Shank’s rival before Akagami lost his arm. I think he is called Hawk eye because he has (one of) the most advanced Observation Haki in the world, and probably one of the most advanced Armament Haki, that’s why his sword is called the strongest black sword. 9. Borsalino: He is probably the fastest man in the One Piece World and one if not the most dangerous marine. He is unpredictable and scary as hell, but that’s also why he is at 9th place, he doesn’t cares that much or at least it looks like it. Until now, he is the marine who we have seen the most, but also the one (with the exception of Green Bull) which we know the least. 10. Fujitora: Doflamingo called him and Green Bull “true beasts” and he has a Devil Fruit that makes me see most of the other devil fruits like toys, he controls gravity, and with it he brought an space rock (meteor or comet) to his fight against Law. I think he has the 2nd most destructive devil fruit and could destroy the world if he wanted to. In his fight against Zoro with just one clash of their swords he send Zoro deep underground, and to sum up more feats, he has no eye sight, so that makes me think he has the strongest and most advanced Observation Haki. By the way, against Sabo he was “playing”, he didn’t take that fight seriously.