Yonko are the four most powerful pirates in the world One Piece. They rule the New World, which is the most dangerous part of the Grand Line, with absolute authority, rivaling even the navy and government, taking several territories under their protection, along with forming alliances with several pirate crews. In the new world there are only two ways to survive; to either become a Yonko, or to serve under a Yonko.
Apparently Yonko are monstrously powerful individuals, but not all strong characters in the world One Piece can become a Yonko. There are some who are so powerful that they could have easily served as an emperor but ended up doing so for one reason or another.

9 Strongest Non-Yonko Pirates in One Piece, Ranked
Yonko are powerful, but they are not the only strong pirates in One Piece.
6
Shiki
Shiki is one of the most prominent characters from the Gol D. Roger generation still active at sea. Known as the Golden Lion, Shiki was once a member of the Rocks Pirates and sailed with the Rocks D. Xebec. He is known to be incredibly powerful, so much so that he was one of the greatest pirates after Rock's era. Shiki assembled the largest armada and even challenged Roger on several occasions. It was clear to see that he had extremely high level strength.
Shiki's total powers were at such a level that he could challenge both Sengoku and Garp at the same time. In their battle, he proceeded to destroy half of Marineford despite the presence of these two powerhouses. He was eventually imprisoned in Impel Down, but ended up escaping from there by chopping off his own legs with the power of Fuwa Fuwa Nomi. Shiki was almost unstoppable in battle. For some reason, he never ended up becoming an emperor of the sea. Even without his legs, Shiki should have been more than capable of getting up to this position. His current whereabouts remain unknown.
5
Loki
Loki is one of the most powerful characters in the world One Piece. Immediately after his birth, it was incredibly clear that Loki was an absolute monster; however, his powers were taken to the next level 14 years ago, when he proceeded to consume the Ryu Ryu no Mi, Model: Nidhogg. In addition to that, Loki also continued with Ragnir, a legendary hammer previously wielded by the war god Elbaf. All of these powers combined took Loki beyond the level of most characters living in the world of One Piece. In fact, even the Emperors of the current era would struggle to handle him, with the sole exception being Shanks.
Loki set out to sea 14 years ago and was out on the seas for 8 years before Shanks finally brought him back to Elbaf. In those 8 years, Loki could have easily achieved the title of an Emperor, especially since Shanks was not part of the Yonko at this time.
4
Dracule Mihawk
Dracule Mihawk is one of the most powerful characters in the One Piece world. He is known to be the world's strongest swordsman and was a former rival of redheaded Shanks. Shanks and Mihawk are said to have engaged in several duels over the years, with each calling across the Grand Line. Their duels remain a draw to this day, meaning that all of their battles ended in a draw. Given that Mihawk was comparable to Shanks in terms of power, it's no surprise to learn that he was also a Yonko-level individual and continues to operate at this level even today.
Mihawk could easily go on to become emperor if he wanted to. However, he doesn't like the extra attention that comes with it. Mihawk doesn't want to be hunted by the marines, nor does he want to be targeted by a younger generation of pirates. As such, he prefers a rather quiet life that he can only live by staying away from the lofty titles of Emperor. Without a doubt, Mihawk is very powerful, and if he were to seriously try to become a Yonko, he could easily become one.
3
Trafalgar law
Trafalgar law is one of the most powerful individuals in the world One Piece from the next generation. He is part of Luffy's generation, and his strength is growing at a remarkable rate. It was recently seen in Wano how Law managed to utilize his abilities in the fight against Big Mom. It was largely due to his efforts that Big Mom was defeated, and he accomplished all of this without breaking the bank as a pirate.

One Piece: Every Yonko's Strongest Attack, Ranked
Yonko are the strongest pirates in the One Piece world, and here are their most powerful attacks.
The team can still grow stronger and utilize powers such as Conqueror's Haki, among others. He was recently defeated by Blackbeard, but the fact that he has a 3 billion berry bounty, similar to that of Luffy, means that Law is operating on a similar strength. After growing stronger after Wano, Law should be able to compete with the likes of the Emperors and even hold on to the title. The only thing holding him back is a weak pirate crew. If the Heart Pirates manage to increase their powers by a large margin, then Law would certainly be a worthy rival to any Yonko living in the world of One Piece.
2
Eustace Kid
Eustace Kid is a monstrously strong pirate in the New World. Just like Luffy and Law, he has a 3 billion carry price which makes him extremely infamous. Kid fought both Big Mom and Kaido in Wano. In the fight against Big Mom, he was instrumental in knocking her down from Onigashima and defeating her. Without Kid beating the emperors in the Wano Country arc really wouldn't have been possible.
When Kid found out that Luffy was made a Yonko instead of him, he really felt robbed. This is especially true given that their rewards are equal, and Kid fully believes that Luffy is his equal, if not even stronger. In the final saga, Kid was completely dismantled by redheaded Shanks in a single swing of the blade, showing the difference between them. It must also be remembered that Shanks is the strongest of the Yonko at this point. Kid should still be in contention for the Emperor's spot, especially if his pirate crew grows stronger.
New questions added!
GameRant Quiz
Start
Light (15s)Medium (10s)Hard (5s)Permadeath (5s)
1
Wang Zhi
If there is one character that could have become a Yonko over the years, this was it Wang Zhi, known to be a former member of the Rocks Pirates. Wang Zhi is known to have taken command of Pirate Island after the death of Rocks D. Xebec. For decades he held control of this island until he was eventually deposed by none other than Blackbeard during the Rocky Port Incident.
In all these decades, Wang Zhi could easily have become emperor. In fact, it's entirely possible that before Shanks, it was Wang Zhi who served as the Fourth Emperor of the Sea, given that he controlled Pirate Island, one of the most dangerous and important places in the pirate world. His current whereabouts remain unknown to fans, but if he wasn't a Yonko, then he was obviously robbed of the title, as the influence he carried was immense.
One Piece chapter 1178 will be available to read on March 29, 2026 on Manga Plus.