The deciding factor in most battles in One Piece is Haki, which seems to be portrayed as the strongest power in the series, surpassing even Devil Fruits. Fighters who can use all three types of Haki, as well as those who can use advanced forms of it, are especially dangerous.
Armament Haki and Observation Haki can be learned through training, while the Color of Conqueror can only be used by those who are born with the rare traits of a Supreme King. This power directly grows stronger as the user becomes stronger overall.
Even among Conqueror's Haki users, only a few of the mightiest can evolve it to its advanced stage, achieving a whole new level of strength. The most resolute individuals have greater willpower, which results in a more powerful Haki, allowing them to potentially overcome any obstacle.
Disclaimer: This article contains major spoilers from the One Piece manga up to chapter 1081 and reflects the writer's personal views.
From Koby to Xebec, the major Haki users in One Piece, ranked worst to best
40) Koby
Koby is an impressively skilled user of the Observation Haki, having an innate predisposition for this ability. His Armament Haki is strong enough to bare-handedly block a Haki-enhanced arrow from the Kuja tribe.
39) Sanji
Even though at times he underperformed, Sanji has a talent for Observation Haki. His best feat was to avoid a projectile from Katakuri. Concerning Armament Haki, Sanji used it to block Judge Vinsmoke's spear. He can also use it to enhance his exoskeleton, allowing him to perform Ifrit Jambe.
38) Donquixote Doflamingo
Doflamingo can use all three types of Haki. He used the Color of Armament to successfully block Gear 2 Luffy's Jet Gatling and Law's Ope-Ope spatial cuts. He can make the weaklings faint by exerting the Color of the Conqueror's.
37) Portgas D. Ace
Ace can use all three types of Haki. His Haki has a fiery nature, to the point that his very presence was able to stop blizzards on an island for as long as he was there.
36) Denjiro
The strongest member of the Red Scabbards, Denjiro can flow his Armament Haki, using an advanced level that even allowed him to cut through Kaido's tough skin. Still, he wasn't able to inflict any serious damage on him, not even after joining his efforts with the other Scabbards.
35) Marco
As Whitebeard's right-hand man, Marco should at least be a decent Haki user. Coating his legs with Armament Haki, he was able to physically touch Logia-user of the caliber of Admiral Kizaru and Admiral Aokiji. However, he failed to do the same with Admiral Akainu.
34) Yasopp
Being able to use the "Future Sight" ability with proficiency not below that of Katakuri, Yasopp is a great Observation Haki user. Given his status in the Red Hair Pirates, he is likely a refined Armament Haki user as well.
33) Eustass "Captain" Kid
Eustass Kid can use all three types of Haki, but he relies almost completely on his Devil Fruit abilities. He is yet to showcase any notable feats using Haki. Still, being a prominent Worst Generation member, he should be able to use at least the basics.
32) Trafagar D. Water Law
Law can unleash intense enough Haki to completely revert the effects of Doc Q's Devil Fruit. Coating his arms with Armament Haki, Law could block Doflamingo's Five Color Strings, an attack strong enough to slice a meteorite from Admiral Fujitora and take out a large portion of Dressrosa's Royal Palace.
31) Lucky Roux
Roux is yet to showcase his capabilities Still, being the third strongest member of the mighty Red Hair Pirates, who base their effectiveness on Haki rather than on Devil Fruit powers, it can be legitimately inferred that he is a powerful Haki user.
30) Boa Hancock
Boa Hancock can use all three types of Haki. She is the leader of the Kuja Tribe, who are all Haki users in their own right. However, Boa's Devil Fruit abilities have been emphasized much more than her usage of Haki.
29) Jinbe
Jinbe is a very experienced Armament Haki user. Hardening his arm, he could block a direct attack from Big Mom. Combining Haki with Fishmen Karate techniques, he straight-up overpowered Who's Who, a Rokushiki user enhanced with Armament Haki and an Ancient Zoan.
28) Don Chinjao
Chinjao can use all three types of Haki. Focusing his Armament Haki on his drill-shaped head, Chinjao was able to perform headbutts that packed enough power to split the Ice Continent in half.
27) King
King can enhance his sword with Color of Armament Hardening. He was able to clash with Zoro's Armament Haki-empowered sword and even overwhelm him. However, when Zoro unleashed his Conqueror's Haki, King ended up overpowered, with his sword cut in half.
26) Rob Lucci
Lucci's Armament Haki-hardened fists clashed on par with those of current Luffy, despite the latter using Color of Armament as well. It may have inferred, though, that Luffy wasn't going all out. Hardening his claws, Lucci was able to pierce through Sentomaru's advanced-grade Haki defense.
25) Sabo
Sabo is rumored to be a notable user of Armament Haki, possibly even using an advanced version of this power, which he can combine with his martial arts style. He easily overpowered Jesus Burgess, a prominent member of the Blackbeard Pirates, breaking his Haki-infused armor.
24) Charlotte Katakuri
Katakuri can use all three types of Haki. A very skilled Observation Haki user, he can even see ahead in the future. His Armament Haki is notably superior to that of Luffy during the Whole Cake Island Arc. He was born with the Color of Conqueror, but he wasn't strong enough to use the advanced level of this ability.
23) Aramaki "Ryogyoku"
Being a Marine Admiral, Ryogyoku is bound to be a notable Haki user. He can use Armament Haki to harden the tips of the branches he creates using his Devil Fruit.
Ryogyoku carries a katana that some fans speculated to be a Black Blade, but as of now, nothing concerning that sword and his proficiency in wielding it is known, leaving the subject open to speculation.
22) Marshall D. Teach "Blackbeard"
Being a Yonko, Teach is bound to be a notable Haki user. Although he seems to mostly rely on his Devil Fruit powers, he has showcased Armament Haki strong enough to successfully withstand S-Hawk's slash, an attack that split Amazon Lily's biggest mountain in half.
21) Borsalino "Kizaru"
In combat, Kizaru mostly relies on his Devil Fruit abilities. Still, being a Marine Admiral, he is bound to be a notable Haki user. He has demonstrated the usage of Advanced Armament Haki.
Emitting his Color of Armament together with that of Akainu and Aokiji, Kizaru was able to completely disperse a devastating quake generated by Whitebeard during the Paramount War.
20) Kuzan "Aokiji"
In combat, Aokiji mostly relies on his Devil Fruit abilities. Still, being a Marine Admiral, he is bound to be a notable Haki user. He showcased some of his capabilities during the Paramount War.
Using his Advanced Armament Haki along with that of Akainu and Kizaru, Aokiji completely negated the devastating quake generated by Whitebeard. He also dodged Whitebeard's bisento, allegedly using Future Sight.
19) Issho "Fujitora"
Being a Marine Admiral, Fujitora is bound to be a notable Haki user. He easily clashed with Sabo, an expert Armament Haki user in his own right. Being immensely skilled with Observation Haki, he uses it to compensate for his blindness. He can perceive anything and handle attacks without difficulty.
18) Yamato
Yamato can use all three types of Haki. She possesses the rare Conqueror Haki, and is one of the very few people who can utilize the upgraded version of this power. The usage of Advanced Conqueror's Haki allowed her to temporarily clash with Kaido. She can also use Haki to project her swings at long distances.
17) Benn Beckman
It was stated that Benn's Haki is comparable, if not superior, to that of the Marine Admirals. His Haki-enhanced bullets can penetrate any enemy, allowing him to turn a flintlock rifle into a fearsome weapon.
16) Sakazuki "Akainu"
Being the strongest among the Admirals, Akainu is bound to be a notable Haki user. Using his Advanced Armament Haki along with that of Kizaru and Aokiji, he completely negated the devastating quake generated by Whitebeard.
15) Roronoa Zoro
Zoro can use all three types of Haki. He is extremely proficient with Armament Haki, to the point where he can deeply cut Kaido's skin and withstand the Hakai. A testament to his potential, he can even use the Advanced Conqueror's Haki.
When going all-out, Zoro exerts all his Haki in the King of Hell Style, coating his swords with Color of Armament and Color of Conqueror. His Observation Haki has developed enough that he can react to incoming attacks even in his sleep.
14) Oden Kozuki
Oden can use all three types of Haki. A true master of the Color of Armament, he was able to significantly injure Kaido, leaving him with a scar. Oden used to wield the Haki-draining sword Enma with the utmost ease, while even Zoro, at least during the Wano Arc, needed to go all out to operate it.
13) Charlotte Linlin "Big Mom"
Big Mom can use all three types of Haki. The clash between her Conqueror's Haki and that of Kaido created a massive shockwave that split the skies. She can combine the advanced applications of both Color of Conqueror and Color of Armament.
12) Sengoku
Sengoku can use all three types of Haki. He is yet to showcase his capabilities, but, being a legendary Marine and a former Admiral, he is bound to be an outrageously powerful Haki user.
11) Monkey D. Luffy
Luffy can use all three types of Haki. A testament to his exceptional prowess, despite his young age he can use advanced versions of Observation, Armament, and even Conqueror's Haki.
In Wano, Luffy's Haki blossomed to the point where it ascended to the level of the strongest characters in the series. Coating himself with Conqueror's Haki and Armament Haki, he has even overcome Kaido in their final clash.
10) Kaido
Kaido can use all three types of Haki. A fearsome fighter with no weaknesses, he is able to combine Advanced Conqueror's and Advanced Armament to enhance his strikes, for devastating results. Using Future Sight, he can avoid particularly dangerous attacks.
9) Monkey D. Dragon
Dragon's fighting abilities are unknown. However, his status as the most wanted man by the World Government, as well as the fact that he is part of the Monkey D. family like Garp and Luffy, hint at him being an outstanding Haki user.
8) Silvers Rayleigh
Rayleigh can use all three types of Haki. He is immensely skilled with the Color of Armament, having fully mastered its advanced application. The strength of his Conqueror's Haki has been directly compared to that of Shanks. He taught Luffy how to use his Haki powers.
7) Ryuma Shimotsuki
Ryuma holds immense hype. He was even compared to Joy Boy. A testament to the might of the strongest samurai in Wano history, he was able to turn his sword Shusui into a Black Blade, which emphasizes the power of his Armament Haki.
6) Edward Newgate "Whitebeard"
Whitebeard can use all three types of Haki. His Advanced Conqueror's Haki was comparable to that of Gol D. Roger. His Observation Haki was good enough to allow him to counter attacks even while asleep. In his sick and aged incarnation, he stopped being able to use Haki, apart from brief fits of rage.
5) Dracule Mihawk
Fans have only seen a glimpse of what "Hawk Eyes" can do. Still, he forged his Yoru into a Black Blade, the strongest sword, and taught Zoro, notably helping him improve. As the World's Strongest Swordsman, who surpasses even Shanks, Mihawk is certainly an outstanding Haki master.
4) Shanks
Shanks can use all three types of Haki. Exerting his Color of Conqueror, he can stop others from using their Observation Haki, and even force into submission fighters of the caliber of Admiral Ryogyoku.
Coating his sword with Conqueror's Haki, "Red Hair" beat Eustass Kid with a single blow. Moreover, Shanks can use Future Sight to see at least ten seconds ahead, and has Armament Haki strong enough to block a magma-enhanced punch from Admiral Akainu.
3) Monkey D. Garp
Garp can use all three types of Haki. In his prime days, he was able to fight on equal grounds with Roger. Garp became known as "The Fist" for the raw power of his punches, which combined the might of Armament Haki and Conqueror's Haki. Even as an old man, he can destroy a town with a single punch.
2) Gol D. Roger
Roger can use all three types of Haki. He could clash equally with Whitebeard despite the latter possessing a mighty Haki and the most destructive Devil Fruit. Their collision caused the surroundings to be completely blown away.
Roger's willpower was immense, resulting in the might of his Haki. This trait was indeed the decisive factor that allowed Roger to conquer the Grand Line and become the Pirate King.
1) Rocks D. Xebec
The exact level of Xebec's Haki powers is yet to be directly showcased, but the fact that Roger and Garp needed to combine their efforts to beat him implies that his prowess is beyond the scope of even the strongest top tiers.
Final thoughts
While many characters weren't strong enough to make the top 40 list, they are still major fighters with Haki prowess that deserves an honorable mention:
- Inuarashi - He can enhance his swordsmanship with Armament Haki flow.
- Nekomamushi - He can enhance his swordsmanship with Armament Haki flow.
- Ashura Doji - He can use Armament Haki flow.
- Sentomaru - He is able to use Advanced Armament Haki for both offensive and, especially, defensive purposes.
- Vista - A Commander-level Haki user.
- Jozu - A Commander-level Haki user.
- Kaku - He can combine Armament Haki Hardening with Zoan Awakening and masterful usage of the Rokushiki.
- Enel - Combining his Observation Haki with the powers of the Rumble-Rumble Fruit, he has immense perceptive abilities.
- Queen - A Commander-level Haki user.
- Cracker - He was able to wound Luffy, despite the latter being in his Gear 4 form, enhanced with Armament Haki.
- Smoker - He is able to inflict notable damage with his Armament Haki-enhanced physical blows.
- Vergo - He can use the Color of Armament to enhance his attacking power with weapons and Rokushiki. He also can cover his entire body with Armament Haki.
- Pica - He can cover his entire body with Armament Haki.
- Kawamatsu - He can use Armament Haki flow through his sword.
- Kinemon - He can flow Armament Haki through his sword.
- Izo - He can shoot bullets enhanced with Armament Haki.
- Who's Who - He can use Armament Haki-enhanced Rokushiki, in combination with the powers of an Ancient Zoan.
- Ulti - A pretty decent Haki user, she uses the Color of Armament to enhance her headbutts.
The idea that a superior Haki equates to a stronger character can't be true for every single comparison, but, for the most part, it is. According to Kaido, Haki surpasses all the other powers and is the asset that allowed Roger to become the King of Pirates.
Garp's feat in the latest chapter, which is even more impressive considering his old age, confirms that those who are able to use Advanced Conqueror's Haki are inherently among the strongest by the mere virtue of wielding that power.