Devil Fruits are a major source of power in the world of One Piece as they grant tremendous power to those who eat them in exchange for the ability to swim. While most strong characters in the story possess Devil Fruit powers, not all of them have one.
Characters such as Shanks rely on other powers, such as Haki, to fight the strongest in the story and manage to keep up with them without even relying on Devil Fruit powers. Other powers, such as scientific technology, also add to the vast arsenal of powers that can be used without relying on Devil Fruits.
10 Hell Memories Could Burn A Yonko Commander Easily
Hell Memories is an extremely powerful technique used by Sanji and it appears to be the pinnacle of his fire-related powers in the story. This power appears to be accessible only when Sanji is burning up with rage, meaning the angrier he gets, the stronger the technique becomes.
Sanji used Hell Memories against Wadatsumi on Fishman Island and later against Queen the Plague on Onigashima. With its extreme firepower, Queen was sent flying in agony.
9 Ryu No Ibuki Can Destroy Things From Within
Used by none other than the Revolutionary Army's Chief of Staff, Ryu no Ibuki is an extremely dangerous technique that relies on the Ryusoken fighting style. By finding a target's core, Sabo is able to send a shockwave of Haki directly to the center, piercing the exterior defense quite easily. As such, the target implodes and is destroyed from within.
Due to how this technique works, it is highly likely that it relies on the usage of Internal Destruction Ryuo that was explained in Wano Country.
8 Kiki Kyutoryu: Dead Man's Game Is Zoro At His Strongest
Roronoa Zoro's strongest technique, called Dead Man's Game, was unleashed by him against Kaido on Onigashima's rooftop. This technique was quite powerful and allowed him to slice Kaido across his chest. It must be noted, however, that normally, this technique isn't nearly as powerful.
Zoro accidentally managed to infuse this technique with Conqueror's Haki, likely due to Emma's ability to draw out excessive Haki from the user, which could've led to Zoro's latent Conqueror's Haki awakening.
7 Conqueror's Haki Infusion From Luffy Put Kaido On His Back
Luffy's fight against Kaido saw him throw everything that he had against the Yonko and although he was successful in hurting Kaido, he wasn't able to bring him down with just Ryuo alone. To stand a chance of defeating him, Luffy had to learn how to infuse Conqueror's Haki into his attacks.
Once he succeeded at this, just a mere punch from him was able to knock Kaido down on his back, which was extremely impressive.
6 Garp's Fist Was Powerful Enough To Destroy 8 Mountains
A Vice-Admiral of the Navy, Garp is known to be the strongest of all the Marines in the story. He was a rival to the Pirate King, Gol D. Roger, and possessed the power to fight on equal footing against him. Garp is a known specialist of Armament Haki.
In his fight against Chinjao, he claimed to have destroyed 8 mountains to dust while warming up to crush his head, which he managed to do successfully.
5 Conqueror's Haki Infusion From Big Mom One-Shot Page One
Just like Luffy and Kaido, Big Mom can also infuse her body with Conqueror's Haki and make herself much stronger. On Onigashima, Big Mom was seen making use of this power against Page One when he approached the Straw Hat Pirates.
Upon hearing that the people of Okobore Town were hurt, Big Mom unleashed a powerful Conqueror's Haki punch that was powered up by Ryuo to knock Page One out completely.
4 Kamusari Sent A Samurai Like Oden Flying
Kamusari is quite a powerful technique and it was used by the Great Pirate, Gol D. Roger on Kozuki Oden. When the two met on the Grand Line, Roger welcomed Oden by sending a shockwave of Conqueror's Haki towards him, sending him flying miles away.
Oden, who was able to take on Whitebeard in battle, was unable to even clash blades with Roger. Kamusari certainly isn't Roger's strongest technique, however, it is definitely up there with the best.
3 Togen Totsuka Gave Kaido His Only Scar Until Recently
Togen Totsuka was the strongest known technique of Wano Country's strongest Samurai, Kozuki Oden. Using his incredible fighting prowess, Oden became a master of Ryou and it is heavily implied that he learned how to infuse his attacks with Conqueror's Haki as well.
Using this power to coat his blades, Oden was able to scar Kaido and make him bleed heavily. Had Higurashi not interfered in the battle, Oden would've killed Kaido.
2 Raime Hakke Was Able To Take Kozuki Oden Down
Raime Hakke, also called Thunder Bagua, is one of Kaido's strongest abilities in the story. It debuted against Luffy in the Wano Country arc and sees Kaido use Conqueror's Haki to coat his kanabo.
Using both Conqueror's and Armament Haki, Kaido is able to take down almost anyone with a single hit, showing how skilled he truly is with this power.
1 Conqueror Of Three Worlds: Ragnaraku Is Kaido At His Strongest
Kaido used Ragnaraku against Luffy when the two fought on the Onigashima rooftop. Although Luffy survived his Thunder Bagua, Ragnaraku was impossible for him to tank successfully as Kaido was in his hybrid form. What's more, Kaido jumps in the air to perform this technique, giving him extra momentum when he slams his Conqueror's Haki-infused kanabo down.
Without a doubt, this technique is incredibly powerful. Kaido certainly has stronger techniques up his sleeve but fans haven't seen them just yet.