Devil Fruits and Haki take the spotlight in the anime. However, there are other powerful abilities that deserve recognition.
Devil fruits are the main source of power in the world of One Piece. The vast majority of the pirates in the Great Pirate Era, along with other powerful fighters in the story, have eaten Devil Fruits. The select few who stand among the elites without any Devil Fruit powers are avid users of Haki.
Haki is yet another powerful ability in the One Piece world only a handful of people can make use of, however, there are other ways to reach the top as well without using it. While Haki and Devil Fruits are surely ways for one to establish themselves among the elites, they are certainly not the only ways.
6. Fishman Karate
Fishman Karate is one of the strongest martial arts styles in the One Piece world. It is primarily used by the Fishmen and the Merfolk, however, can also be used by normal humans if taught properly. Fishman Karate relies on the basis of the manipulation of water in the atmosphere.
Since Most things in the surroundings, including humans, have a great content of moisture within, Fishman Karate can manipulate it and deal damage from within. This form of fighting is extremely impressive, as seen on several occasions in the story already. Jinbe, the Helmsman of the Straw Hat crew, is a master of the Fishman Karate and, he is yet to show the fans what he can do with it at the best of his abilities.
5. Rokushiki
The Rokushiki is another powerful style of fighting in the One Piece world that is known to be unique to the World Government. It was most likely developed by the strong fighters within the ranks of the Government and, sometimes, it also extends to the members of the Navy. The Rokushiki is usually utilized by the members of the Cipher Pol. During the Water Seven saga, fans saw the CP9 make use of these powers.
While some of them are Haki based, such as Tekkai, others have no connection to Haki and deserve a special mention, such as Soru. Those who have mastered the Rokushiki gain access to a unique ability called the Rokuogan, which allows the user to fire powerful shockwaves from their fists, capable of dealing damage from within. Rob Lucci is the only user of this ability so far.
4. Lunarian Power
Several races in the world of One Piece are blessed with their own special abilities. The Lunarian race is, quite possibly, the most overpowered race in the One Piece world. Although now nearing extinction, the Lunarians are known to have an incredibly high tolerance for harsh conditions, such that they can survive in nearly any physical environment.
Those of the Lunarians have white hair, brown skin, giant black wings, and an eternally burning flame on their back. They have an incredibly high defense and even the strongest attacks in the series will have trouble piercing their armor. They also have the ability to manipulate flames easily. At the same time, those who possess the power of the Lunarians can also gain extreme speed in exchange for their high durability. Without a doubt, this race would make one overpowered even without the usage of a Devil Fruit and Haki.
3. Germa Scientific Enhancements
The Germa scientific enhancements are key to understanding the truth behind the Devil Fruits, among other major power sources. This is simply down to the fact that the scientific enhancements of the Germa Kingdom are entirely based on Lineage Factor Manipulation, which, in other words, means altering the DNA.
Vinsmoke Judge, the leader of the Germa Kingdom, experimented upon his children and scientifically enhanced them to become superhumans. They gained powers such as an incredibly tough exoskeleton, superhuman strength, speed, and an incredibly high regeneration factor, among other things, such as loss of emotions. These powers are incredible and make anyone capable of taking on the elites of the story.
2. Raid Suits
If the Lineage Factor Manipulation was not enough, the Germa Kingdom have another source of power up their sleeve, and this is the Raid Suit. These are powerful suits that the Vinsmoke Family can put on to make themselves stronger. They help them fight to the best of their abilities and make their already incredible bodies even tougher.
Those of the Vinsmokes have an incredible arsenal of weapons, thanks to the Raid Suit. Their scientific prowess is such that even Big Mom, a Yonko of the sea, wanted to get her hands on the abilities of this family. When Sanji put on the Raid Suit, he gained enough durability to withstand attacks that could level an entire city.
1. Power To Control Legendary Creatures
Perhaps the greatest power in the world of One Piece is one that can be classified as neither Haki nor Devil Fruit, and it is one that good potentially shake the entire world and even destroy it in some cases. There exist Ancient Weapons in One Piece, such as Shirahoshi, who possesses the power to destroy the entire world. Shirahoshi can control all the Sea Kings who can level islands and destroy continents.
On the other hand, Momonosuke also has a slightly similar ability through which he can control the giant elephant, Zunesha. While his powers are not nearly as dangerous as Shirahoshi’s at the moment, they still are fearsome.
Src: gamerant.com