Logia (自然系（ロギア） Shizenkei [Rogia]?, literally translated as "Nature System") is one of the three types of Devil Fruit. It is characterized by giving its user the ability to turn into a natural element or force of nature. Logia Devil Fruits are considered the most powerful as well as the rarest of the types of Devil Fruit as a whole.
Logia Devil Fruits allow a person to become a natural element, either in whole or in part; In their default state, they are neither completely human nor element.
Because Logia users can turn their entire body into their element, they are virtually immune to physical harm by conventional means. Any attack will simply pass through or be absorbed harmlessly into their body which, depending on the type of element, can even cause the attack to backfire on the attacker. A Logia user can be shattered, split, or otherwise separated into multiple parts, sometimes down to the size of dust, and reform without injury. The only known exception to this rule would be with Blackbeard, whose Yami Yami no Mi powers actually absorb strikes and make them stronger doing even more harm to himself than normal.
In addition to their ability to become their element, Logia users can generate near-limitless amounts of their element and control it at their whim, giving them fearsome attack abilities. Crocodile's sandstorms, Ace's conflagrations, and Enel's thunderstorms are all examples of the devastation a Logia can bring about. Smoker's and Caribou's powers are exceptions to this, with their elements being better suited for capturing enemies rather than causing destruction.
Logia users can also use their element in other ways related to their element; Crocodile's sand power could be used to absorb moisture, Enel's electricity heat could melt and reshape gold, Aokiji's ability could freeze water, and Kizaru's ability could permit him to travel over beams of light. Logia users can afford them immunity to effects related to their elements as well. For example, Crocodile and Ace are completely unaffected by the desert heat, as they possess Logia powers related to dryness and heat, respectively.
Finally, Logia users' physical strengths do not influence the power of the fruit. Regardless of the original strength of the user, their gained powers are of the same scale. This is different from Zoan fruits, which act as physical strength multipliers, and Paramecia fruits, which can be used in conjunction with the user's physical abilities. The sole exception is Kizaru, who uses his light to augment his kicking strength to explosive levels.
Despite the fearsome power of Logia users, they do have some weaknesses. Sneak attacks are more likely to work, as the user won't be ready to avoid them. However, with training, most Logias learn to become their element by reflex, eliminating the ability to strike them by conventional means. For example, Enel's ability has been trained to the point that he could reflexively change form while asleep. Whether or not Logia users need to become their element repeatedly to dodge every individual attack, or can simply turn their whole body into their element for an extended period of time (possibly even after falling asleep), remains unknown.
Logia users also tend to become seemingly overconfident, as they are unaccustomed to dodging attacks. Thus, if their advantage is neutralized by some means, they have to rely on their ability to dodge, a skill which they may or may not be proficient at. This is somewhat mitigated by the fact that most Logia users shown thus far are extremely tough, even when they are vulnerable.
Another way to harm a Logia is to exploit the element itself, using its properties to solidify the user and render them vulnerable to damage. For example, Enel, being made of electricity, is vulnerable to Luffy's rubber body despite his honed reflexes, since rubber is an insulator. Another example is Crocodile, who, being made of sand, can be struck if his body is dampened (either by getting him wet or striking with wet limbs), since the sand sticks together if wet.
In addition to solidifying the user's body, it is possible to use elemental weaknesses to a further extreme, completely neutralizing the element that makes up the user's body. Even though a Logia user can generate near-limitless amounts of their element, they cannot recover from blows that destroy their main "body", no matter what state it's in. This is first shown by Akainu, whose magma was able to smother Ace's flames, causing him physical damage despite being a Logia user.
A minor weakness is that Logia users can only control their elements when generated from themselves, and not if it is in another state of matter, meaning that they cannot control their respective elements if it was not generated from their bodies. However, this could be bypassed by simply mixing their own element with a pre-existing amount of that particular element in order to augment the strength of the attack (as Crocodile did with his sandstorms). Yet, this only works if there's already a substantial elemental source, such as a desert or a body of water.
Finally, users of Busoshoku Haki can strike Logia users as if they were human; Rayleigh describes it as the ability to "force into solidity the fluid bodies of the near-invincible Logia Fruit users" when he explains it. This is not infallible, however, as both Aokiji and Akainu (Haki users themselves) have both been hit by Haki-enhanced attacks that should have injured them, but have reformed them back to normal. Akainu does mention that it is annoying to fight Haki users, though, suggesting that he took significant effort to resist it.
These Devil Fruits are not limited to the classical elements: fire, water, earth, and air, but also include physical states like smoke and sand. There are two types: tangible (something a person could hold like sand or ice) and intangible (something that could not be held like smoke or fire). Logia Devil Fruits can also be divided into two other types, forms of matter (smoke, sand, ice, lava, or swamp) and forms of energy (electricity, fire, or light). The only known Logia that does not fit into the latter method of categorization is Blackbeard's darkness. It appears that Logia users transformed in intangible elements such as light can still be pushed (as demonstrated when an explosion blasted Kizaru).
However, amongst some Logia fruits there seems to be an order of superiority. Akainu's magma completely overpowered Ace's fire. This left Ace in a state in which no medical aid could possibly hope to save him. This is an example of the danger of placing an inferior Logia against a superior one. Something almost all Logia users seem to share (except for Marshall D. Teach), is they are not used to getting hit due to being so used to their virtual invincibility, and are visibly shaken when they are harmed, despite their resilience.
Many users of Logia fruits seem to have created their own form of personal transportation and use their abilities to power these devices. Among these are Ace's Striker, a small ship powered by his flame powers, Smoker's Billower Bike, a three wheeled bike powered by his smoke powers, Aokiji's Ao Chari, a bicycle which he uses to cross the sea, freezing a small line in the water to ride on and Enel's Ark: Maxim, a ship which uses gold as a conductor for Enel's electric ability to power the ship.
List of Known Logia Fruits
- Moku Moku no Mi (English Versions: Smoke-Smoke Fruit/Plume-Plume Fruit): Element of smoke.
- Mera Mera no Mi (English Versions: Flame-Flame Fruit/Flare-Flare Fruit): Element of fire.
- Suna Suna no Mi (English Versions: Sand-Sand Fruit): Element of sand.
- Goro Goro no Mi (English Versions: Rumble-Rumble Fruit): Element of lightning.
- Hie Hie no Mi (English Versions: Chilly-Chilly Fruit/Ice-Ice Fruit): Element of ice.
- Yami Yami no Mi (English Versions: Dark-Dark Fruit): Element of darkness.
- Pika Pika no Mi (English Versions: Glint-Glint Fruit): Element of light.
- Magu Magu no Mi: Element of magma.
- Numa Numa no Mi: Element of swamp.
- Toro Toro no Mi: Element of some unknown liquid. (Movie 2)
- Ame Ame no Mi: Element of semi-liquid and liquid candy syrup. (Movie 4)
- Pasa Pasa no Mi: Element of paper. (Video Game)
- Due to the rarity of the class, the Logia has the third lowest known amount of users (if Mythological and Ancient Zoans are counted as different types of fruit, that is; if not, it's the rarest). To go along with this idea, most shown Logia fruits seem to belong to extremely powerful organizations (three Marine admirals and one Marine commodore, one Whitebeard Pirate commander, two former Shichibukai, and the former god of Skypiea). Caribou is the first and only known canon exception to this, a rookie pirate captain, though he still has an incredibly high 210,000,000 bounty.
- The three non-canon Logia fruits are all of peculiar elements and seem inferior to a typical Logia, as they are seemingly unable to produce mass-destructive attacks.
- The word "Logia" is a Greek word from New Testament scholarship that translates roughly as "sayings, utterances, oracles". It is surmised that given the kanji, this type of Devil Fruit is meant to represent an element of nature "speaking" with force; always with a destructive capacity.