One of the most powerful combatants in the Straw Hat Pirates, Sanji has played an integral role in the journey of Luffy and his crew through the Grand Line in One Piece, since his introduction in the Baratie Arc. Known as "Black Leg Sanji" for his ferocious kick-based fighting style, he became a pirate in order to seek out the All Blue, a specific location where all the world's seas meet.

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Having honed his skills as a chef while defeating many powerful opponents along the way, Sanji's character has undergone a considerable degree of development throughout One Piece, especially during the Whole Cake Island Arc. That being said, there are certain aspects of his character that have remained the same over the course of his journey. Some of these traits have been to his detriment, culminating in him being rendered completely incapacitated and unable to fight without external aid.

5 Overconfidence

Sanji has always been hot-headed and prideful about his fighting skills from the very start. Even his interactions with Zeff at the Baratie often escalated without warning, leading to the pair yelling at each other and threatening physical violence. After joining the Straw Hat Pirates, much of this anger and arrogance is often directed at his closest rival Roronoa Zoro, who is also one of the crew's strongest fighters.

More often than not, he believes himself to be stronger than most of the Straw Hats, including Zoro, which has been a point of heated debate in the series for quite some time now. His overconfidence is not limited to this, but also when ascertaining the strength of his adversaries. On occasion, he can be easily provoked and quick to rush into battle without a second thought, sometimes underestimating his opponent and coming out the worse for it, as seen in his fight against Vergo, where the latter's Tekkai was hard enough to crack Sanji's shin-bone after repeated attacks.

4 Lack Of Conqueror's Haki

As One Piece enters its Final Saga, one of the most important skills to ascend to the highest ranks of the pirate world is undoubtedly Conqueror's Haki. Where Luffy awakened it as far back as the Marineford Arc, Zoro was able to tap into it more recently during the Raid on Onigashima at the conclusion of the Wano Country Arc. This leaves Sanji as the only member of the original Monster Trio who is yet to awaken it.

Although he is quite adept at using both Armament and Observation Haki, there is no doubt that he will need Conqueror's Haki when facing off against more powerful opponents such as the Admirals or the Five Elders. With this in mind, Sanji's lack of Conqueror's Haki is something that could be compensated for by his genetic enhancements, but there will definitely come a time when even those power-ups may not cut it. Just like Zoro, Sanji might also have to accept his desire to conquer, and potentially unlock the Color of the Supreme King in the process.

3 Fighting With His Hands

Perhaps the most prominent feature of Sanji's fighting style is his reliance on kick-based attacks and his refusal to use his hands in combat. This stems from his belief that his hands are meant for cooking, and as such, he does not believe in sullying them through violence. He also does not want to cause any injury to his hands by fighting, which is another reason behind his unique Black Leg Style.

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Despite this, there may come a time when Sanji's legs are either immobilized or rendered ineffective when fighting opponents with many more limbs than him, which is where his refusal to use his hands may come to become a problem. While this scenario has not presented itself as yet, it is not entirely impossible, considering that the Straw Hat Pirates will only face stronger opponents as the Final Saga progresses. Hence, even though it is not a glaring weakness at present, there is always a chance that stronger adversaries may just exploit it.

2 Sense Of Masculinity

As seen from the period he spent stranded in the Kambakka Kingdom during the time skip, Sanji is quite terrified of anyone undermining his masculine identity. When he encountered the okama of Momoiro Island, Sanji was thoroughly disturbed by their attempts to make him one of their own. He strived to flee from their clutches, only to be eventually convinced into becoming one of them by donning a dress, wig, and makeup, as his sense of identity eroded.

The subsequent arrival of a News Coo who delivered information about the Summit War of Marineford shocked him back to his old self. In the period that followed, Sanji spent much of his time running away from the okama pursuing him. Over time, his leg strength reached superhuman levels from constant sprinting. This eventually led to him acquiring Geppo, the Rokushiki technique that allows Cipher Pol agents to walk on air. Unfortunately, he now holds a deep sense of revulsion towards okama in general, despite the skills of Attack Cuisine that he learned from them, even though he adores Ivankov.

1 Women

Most One Piece fans would know that there is only really one weakness that truly matters when it comes to Sanji — his amorous and borderline perverted attitude toward women. Although he is quite chivalrous and has a strong moral code that forbids him from ever fighting or striking a woman, regardless of the circumstance, there have been many instances where enemies have taken advantage of this. He is also quick to anger if anyone threatens the female members of the Straw Hat Pirates or any of their traveling companions.

At times, this has been hailed as a noble sentiment by his crew mates, allies, and even some opponents. However, the downside here is that Sanji is also easily distracted by even the mention of a beautiful woman, and will readily drop his responsibilities to chase after them. From his fight against Kalifa in Enies Lobby, to his capture and torture at the hands of Black Maria during the Raid on Onigashima, Sanji has repeatedly left himself at the mercy of those willing to take advantage of this character trait.

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