Renowned as "The Plague," Queen is one of the three right-hand men of Yonko Kaido. He serves as an All-star of the Beasts Pirates crew and is among their three strongest members.
Queen, being a notorious pirate, has a bounty of 1.320 billion berries on his head currently. As expected of someone of his power level, he is likely a proficient user of Haki, and also has an Ancient Zoan Brachiosaurus Devil Fruit. Few characters in One Piece have power greater than that of Queen the Plague and here's a list of 10 of those characters.
10 Benn Beckman
Benn Beckman is the First Mate of the Red-Hair Pirates and a fearsome pirate of the New World. His authority is second only to Red-Hair Shanks in the crew, which just goes to show how capable he truly is.
Benn hasn't been seen in combat yet, however, he is known to have stopped Kizaru in his tracks during the Marineford arc of the series. According to Brannew, he has a high bounty on his head.
9 King the Wildfire
King the Wildfire is the strongest of the three right-hand men of Yonko Kaido. He holds the same rank of "All Star" as Queen the Plague.
However, both in terms of power and bounty, King is likely one level above Queen. Like Queen, he possesses an Ancient Zoan Devil Fruit which lets him transform into a Pteranodon at will and grants great fighting ability to him.
8 Sabo
Sabo is the Commander in Chief of the Revolutionary Army and a famed criminal with a bounty of 602 million berries on his head. His authority and power is known to be second to Dragon himself, which is proof enough that he's stronger than Queen.
During the Dressrosa arc of One Piece, Sabo fought against Fujitora on an even footing, although neither of them were going all out. Nonetheless, having his strength recognized by an Admiral suggests that he's a fierce fighter.
7 Katakuri
Katakuri is the leader of the Three Sweet Commanders of the Big Mom Pirates. His authority is second only to Big Mom herself, which shows how capable and trustworthy he is.
With a bounty of 1.057 billion berries, Katakuri is easily among the strongest pirates in the world of One Piece. He's only ever been defeated once, and that happened recently at the hands of Monkey D. Luffy during the Whole Cake Island arc.
6 Luffy
The Captain of the Strawhat Pirates, Luffy is one of the members of the Worst Generation and the Fifth Emperor of the Sea. Having become a fearsome pirate, Luffy has gained a bounty of 1.5 billion berries, which is higher than that of Queen's.
In terms of fighting prowess, Luffy is, again, on a level above Queen's since he managed to defeat Katakuri. Furthermore, he's gotten even stronger since then and his Haki control has improved drastically as well.
5 Monkey D. Dragon
Known as the "World's Worst Criminal," Dragon is the leader of the Revolutionary Army in One Piece. He is quite a powerful figure whose ability is often put on the same level as the Yonko themselves.
Dragon's right-hand, Sabo, was capable of fighting an Admiral on par, which implies that his own ability is likely much greater. Although his Devil Fruit power remains unknown, Dragon seems to have control over the weather itself.
4 Blackbeard
Blackbeard is one of the Yonko of the Sea and he recently ascended to the position after the fall of Whitebeard. Having defeated Marco and the Whitebeard Pirates, Blackbeard eventually gained a bounty of over 2.2 billion berries, which is staggering.
He wields two Devil Fruit powers, both of which are known to be extremely overpowered, in the Yami Yami no Mi and the Gura Gura no Mi. With them, Blackbeard believes that he's essentially invincible.
3 Shanks
Shanks rose to the position of Yonko about 6 years before the current time period in One Piece. Over the years, he's acquired a bounty of over 4 billion berries, which is astounding, to say the least.
Shanks is a user of all three Haki types and his power is much greater than that of any Yonko right-hand man, which includes Queen as well. Although he's never been seen in a fight, Shanks is easily one of the strongest people in the series.
2 Big Mom
One of the Four Emperors, Big Mom is a known as a Great Pirate and she has a bounty of over 4.3 billion berries on her head. She's known to be one of the biggest powers in the One Piece world right now, her only rivals being the other Yonko.
With the powers of the Soul Soul Fruit, Big Mom is levels above Queen the Plague. When the two clashed in Udon, Big Mom managed to beat him with just a few blows.
1 Kaido
Also known as the King of Beasts, Kaido belongs to the Four Emperors of the One Piece world. He's described to be the strongest creature on land, air, and sea.
Throughout his life, Kaido had been defeated seven times as a pirate, however, every attempt to take his life had failed. It goes without saying that Queen, one of the subordinates of Kaido, is far weaker than him.