The Straw Hat Pirates' cook, Sanji went from strength to strength throughout the Straw Hat Pirates' journey across One piece New world. He had always been incredibly powerful when it came to combat, and now that the Straw Hats were facing serious dangers in the New World, especially in the Final Saga, he had to become even more powerful.
In the final stretch of the story, the straw pirates rose to the level of the Imperial garrison. This means that Luffy's subordinates such as Sanji and Zoro must also reach the next level of power. As such, Sanji has had to overcome many powerful pirates and has already left some elites in the dust.
5
The Vinsmoke Siblings
The Vinsmoke siblings are Sanji's own brothers and were introduced to fans in the Whole Cake Island Arc. There, it was revealed that the brothers were total war machines, capable of destroying countries by themselves.
The Vinsmoke siblings had everything Sanji didn't have – an exoskeleton, a cold heart, and a body capable of taking down almost anyone. However, Sanji had one thing they didn't have, emotions and free will.
The Vinsmoke siblings were very strong, and by the time of the Whole Cake Island arc, some of them, like Niji and Ichiji, could be stronger than Sanji. This is not the case in Final Saga. Sanji had already officially surpassed each of them and had since reached an unprecedented level of power.
4
Donquixote Doflamingo
Known as the captain of the Donquijote Pirates, Doflamingo was a monstrously powerful character that fans saw quite often in the Dressrosa Saga. One piece. Back then, Doflamingo was Luffy's rival that he took down.
However, Sanji had his own fight with him when the two met not far from the Green Bit. Doflamingo was then able to completely overpower Sanji, even though he acknowledged his incredible strength. Sanji was overall much weaker than Doflamingo. However, now in the Final Saga, Sanji has become strong enough to defeat him easily without going all out.
3
King
King the Wildfire, whose real name is Alber, was one of the three pirate beast stars. Due to having the highest bounty of all, and the fact that the Beast Pirates are a meritocracy, King was considered Kaid's strongest subordinate. He was incredibly tough and his fight against Zoro was proof that King was not an easy opponent. Sanji had faced the king in combat on numerous occasions and had been able to hold his own each time, suggesting that there wasn't much of a difference between the two in terms of strength and skill.
However, once Sanji awakened and unleashed his hidden abilities, he reached a level that far exceeded that of King. Right now, Sanji has enough in him to easily defeat the king in battle without going all out.
2
Charlotte Katakuri
Charlotte Katakuri is the strongest of the Sweet Commanders of the Big Mom Pirates. Known as an incredibly powerful pirate with the ability to see the future itself, Katakuri is superior to Sanji when it comes to using Observation Haki. Overall, however, as a fighter, Sanji far surpasses him in every aspect of battle.
After awakening his hidden abilities, Sanji reached a level far beyond that of the first Yonko commanders. Only a handful of individuals can take him on and defeat him in battle, and Katakuri is definitely not one of them. A fight between these two individuals would surely be incredibly enjoyable for fans as they both excel at using Observation Haki.
1
Marco
Known as the former commander of the first division of the Whitebeard Pirates, Marco is an extremely powerful pirate and his strength has been recognized even by the likes of the Five Elders. In the Paramount War arc, Marco is shown to be strong enough to fight the Marine Admirals and give them a hard time.
Marco is an incredibly powerful character and the power of his Phoenix Devil Fruit ensures that he can recover from all injuries if he has enough stamina. While it's certainly debatable who is stronger between Marco and Sanji, the latter has incredible toughness along with a very high recovery rate. Also, the offensive power he has far surpasses anything Marco has in his arsenal, and the fact that he was able to destroy even Kizaru's light and shock him, which even Marco couldn't, clearly indicates that Sanji is far more impressive than Marco.
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