Mera Mera no Mi

The Mera Mera no Mi is a Logia-type Devil Fruit that allows the user to create, control, and transform into fire at will. It was eaten by Sabo, and previously Portgas D. Ace.

Etymology

 * "Mera Mera" is a Japanese onomatopoeia of the noise fire makes when it burns.
 * It is called the Flame-Flame Fruit in the Viz Manga and FUNimation dub.
 * It is called the Flare-Flare Fruit in the 4Kids dub and FUNimation subs.

Appearance
The Mera Mera no Mi is a round orange fruit, composed of many flame-shaped components with swirl patterns on each one, and has a swirled stem on the top. It is small enough to be held in one hand.

Strengths
The fruit's major strength, like other Logia types, is that it allows the user to produce as well as become the element they control. In this case, the user is able to create, control, and become fire. With this in mind, they can create devastating fire-based attacks and gain a high resistance towards most heat-based attacks. The flames can also be used to bolster the kinetic force of physical attacks. They are also able to avoid normal attacks by turning into fire and allowing the attack to pass through their bodies. Igniting oneself also has the added effect of burning an opponent if he or she had tried to physically harm the user.

When this power clashes against certain other Logia on equal grounds, this seems to come to a stalemate: neither smoke nor ice was able to overcome nor succumb to the flames, instead cancelling each other out when the two elements collide.

Weaknesses
The Mera Mera no Mi is inferior to the Magu Magu no Mi in the Devil Fruit hierarchy. Magma is of a naturally higher order than fire, allowing it to overwhelm the Mera Mera no Mi's powers. The magma can neutralize even the intangibility and heat-immunity of the Mera Mera no Mi, thus leading the user to be burned and completely vulnerable. If the magma strikes through the body of the user, it cannot be phased through like most other attacks, and the damage inflicted will remain, as with any normal person's body. Other than that, the user is also affected by the standard Devil Fruit weaknesses.

Portgas D. Ace
The fruit's bestowed powers, as used by Ace, have been used in a variety of ways. Since he left home three years before Luffy, who did not know that Ace had powers before their reunion in Alabasta, Ace had his powers for no more than three years. Ace notably used his powers usually either to fight or to propel his raft. Ace shares Luffy's penchant for naming his techniques, with the only difference being that Luffy adds the phrase "Gomu Gomu No", followed by the specific name of the attack (usually inspired by a certain object or concept). Ace names his attacks in Japanese and they are often made of two-word phrases and are based on different mythologies. According to Gatz, Ace had sunk countless battleships and burned down mighty cities with the fruit's power.

During Ace's cover story, the powers of the fruit allowed Ace to rescue a Marine officer and some documents on board a burning ship. Despite being weakened by the Yami Yami no Mi severely during his fight against Blackbeard, Ace was still able to skillfully use the fruit's power to inflict some damage to his former subordinate.

The named techniques that are used by Ace that involve the Devil Fruit are as follows:
 * Kagero (陽炎): Ace shoots a stream of fire from the palm of his hand. This was first seen being used to stop Smoker from catching Luffy. This is called Sun Flare in the Viz Manga and Heat Haze in the FUNimation dub.


 * Hiken (火拳): Ace's apparent signature attack and the source of his nickname "Fire Fist Ace". Ace turns his fist into flames and launches it as a column of fire at his target. This attack is so incredibly powerful that it is able to plow through several ships in one shot. However, it was completely neutralized by Akainu's Dai Funka, and is the final attack Ace ever used prior to his death shortly after. This is called Fire Fist in the Viz Manga and FUNimation translation, Heat Fist in the 4Kids dub, and Flame Fist in the FUNimation dub of "One Piece: Unlimited Adventure".


 * Higan (火銃): Pointing the index and middle fingers of both hands at an opponent like guns, Ace turns his fingertips into flames and shoots bullets made of fire from them. This technique was first seen when Ace retaliated against Van Augur's attack. In the Viz Manga and FUNimation translation, this is called Fire Gun.


 * Enkai (炎戒): Ace amasses a large amount of flames around his body (usually by first swinging his outstretched hand around him, summoning the flames) in preparation for an attack. This is apparently the prerequisite technique before Ace can use Hibashira. In the FUNimation dub and in the Viz Manga translation, this is called Flame Commandment.
 * Hibashira (火柱): Used following Enkai,. Ace shoots the collected flames straight upward, destroying a target above him. It can also be fired downwards to clear any enemies that might be below him while he's in mid-air. This technique and its prerequisite technique were first seen when Jesus Burgess threw a hotel at Ace. In the Viz Manga translation and FUNimation dub, this is called Fire Pillar.


 * Hotarubi (蛍火): Ace creates many small, glowing greenish yellow fireballs that float around an enemy. The idea behind this attack's name is that before he attacks with them, the small fireballs look like fireflies in the air. This move is apparently used in preparation for Hidaruma and was first seen in Ace's battle against Blackbeard. In the Viz Manga translation and FUNimation dub, this is called Firefly.


 * Hidaruma (火達磨): After using Hotarubi to send the fireballs floating around in proximity with the enemy, Ace sends them all flying into the target(s) all at once, burning them. This was first seen being used in Ace's battle against Blackbeard after Blackbeard performed his initial attacks. In the Pirate Warriors games, the fireballs from Hotarubi actually home in targets themselves, while Hidaruma is instead a grab attack where Ace captures his target as he plows them into the ground for an explosion (which he leaps back from). In the Viz Manga translation and FUNimation dub, this is called Fiery Doll.


 * Shinka: Shiranui (神火 不知火): Ace hurls long lances made out of fire. The lances have the combined effect of simultaneously burning an opponent while piercing them. This was first seen being used against Blackbeard when Ace was being pulled forward by the former's power. In the Viz Manga translation and FUNimation dub, this is called Saint Elmo's Fire, a clear reference to the homonym weather phenomenon. The term "Shiranui" or "Shiranuhi" also literally translates to "Unknown Fire".


 * Jujika (十字火): Ace places his index fingers together in a cross shape before launching a cross-shaped column of fire directly at his opponent. In the anime, after crossing his fingers, a cross-shaped ray of light can be seen emanating from the fingers at the target followed by the column of fire. This was first seen being used against Blackbeard after Ace attacked him with Shinka: Shiranui. This attack's name is a pun since "Juujika" refers to crossfire from weapons, yet Ace is making an actual cross out of fire. It also is a possible play on the term juujika (十字架, lit. cross stand/rack), a term used more for the crosses that are meant to crucify people with. In the Viz Manga translation and FUNimation dub, this is called Cross Fire.


 * Dai Enkai: Entei (大炎戒 炎帝): Ace's ultimate technique. After creating great spiraling flames centered on his location before amassing it at a focused point (i.e. the palm of his hand), Ace then turns it into a gigantic fireball resembling the sun and hurls it at his opponent to try to obliterate them. This was only seen being used during the final moments of Ace and Blackbeard's battle. "Entei" sounds similar to "Enkei" meaning "circle," a reference to the attack's shape. In One Piece: Unlimited Cruise, Ace activates this move by first bending his knees slightly and then placing the outstretched palm of his hand towards the ground (with his other hand gripping the wrist for support), where the flames manifest themselves into a sphere. In the FUNimation dub and Viz Manga translation, this is called Great Flame Commandment: Flame Emperor.


 * Enjomo (炎上網): Ace creates a circle of fire around a selected area, preventing anyone from entering or leaving it. This was first seen being used against the Marines in Alabasta under the command of Smoker, and was named in a flashback against Whitebeard. In the Viz Manga, FUNimation subs and dub, this is called Flame Fence.


 * Kyokaen (鏡火炎): Ace releases a wall of fire to block an attack. This was first seen to counter Aokiji's Ice Block: Pheasant Beak, the two attacks canceling each other out. In the Viz Manga, this is called Mirror Flame and Flame Mirror in the FUNimation sub.

Video Game Only Techniques

 * Twin Guns & Cross Fire: Ace fires a volley of bullets from his two guns before finishing the technique with Jujika. This technique appears as one of Ace special moves for his Strong World DLC costume in One Piece: Burning Blood.

Sabo
After Sabo ate the fruit, he has been shown being able to utilize it effectively mere seconds after consuming it. Although struggling to control his new powers at first, he adapted to it, and Sabo has displayed great control over the fruit's abilities, being able to utilize it in conjunction with his pipe and avoid injury by making himself intangible. Like Ace, Sabo names the techniques in Japanese, though Sabo's naming style follows more of his affinity with dragons.

Sabo has been shown using it to enhance the already immense destructive power of his "claws", allowing him to overwhelm powerful foes such as Jesus Burgess.


 * Hiken (火拳): Ace's signature move which was inherited by Sabo after consuming the fruit. Like Ace, Sabo turns his fist into flames and launches it as a powerful column of fire at his target, capable of causing enormous damage and completely shattering a thick layer of stone floor. This was first seen used to destroy the entire Corrida Colosseum stage, and the first move Sabo made since consuming the fruit. He also demonstrated the ability to use the attack at pointblank range, by grabbing onto his opponent's face and then triggering the ignition, sending the target flying backwards with tremendous kinetic force and severely burning them simultaneously, as he did so on Burgess.


 * Moeru Ryusoken: Kaen: Ryuo (燃える竜爪拳 火炎 竜王): A combination of the Mera Mera no Mi powers and his Ryusoken style, Sabo forms his "talons" and ignites them, and then slams them into his opponent and spins them around before blasting his target away with a burst of fire. This was first used against Burgess, who was sent flying a great distance away while suffering from burns of the flames.

Video Games Only Techniques
In One Piece: Pirate Warriors 3, Sabo can use unnamed variations of Ace's Higan, Jujika, along with fire-based versions of his Ryu no Kagizume and Ryu no Ibuki (styled as a Hibashira; the former somewhat predating Kaen: Ryuo), all as normal attacks.


 * Gomu Gomu no Heat Magnum (ゴムゴムの炎神銃 (ヒートマグナム)): A team combination attack used by Luffy and Sabo to defeat Donquixote Doflamingo in the alternate ending of the Dressrosa Arc that appears in One Piece: Pirate Warriors 3. After Kuzan freezes Doflamingo's legs place, Sabo and Luffy stand side-by-side, Luffy activates Gear Second and prepares a Gomu Gomu Red Hawk while Sabo prepares Moeru Ryusoken: Kaen: Ryuo. Luffy then says Gomu Gomu no while Sabo says Heat, then they combine their fire-based punches into a single fireball (through the fire manipulation abilities of the Mera Mera no Mi) as they both shout Magnum. The attack is immensely powerful and capable of burning through Doflamingo's Off White threads and knocking the Shichibukai through a wall. However despite this it apparently lacks the power of the Gomu Gomu no King Kong Gun that defeated Doflamingo in the canon storyline, as Doflamingo was only momentarily knocked out by this technique, though it was enough for Doflamingo to admit defeat and flee. The kanji's literal reading is "Enshinjuu".
 * An alternate version of this technique is performed by Luffy (Gomu Gomu no Red Hawk), Ace (Hiken), and Sabo (Moeru Ryusoken: Kaen: Ryuo) appears at the end of the game's introductory cutscene.

Past
The fruit was first eaten by Portgas D. Ace sometime between when he was age seventeen to twenty. He retained his powers for no more than three years, and gained much infamy by sinking battleships and burning down mighty cities, even before joining the Whitebeard Pirates.During the Battle of Marineford he was killed by Akainu when trying to protect Luffy.

Two-Year Timeskip
After Ace's death at the hands of Admiral Akainu during the Battle of Marineford, the fruit reappeared and was obtained by the Donquixote Pirates.

Dressrosa Arc
The fruit then became the grand prize for whoever won a tournament at the Corrida Colosseum on Dressrosa, with Doflamingo's intent to use it as bait to break apart Luffy's alliance with Law. Upon being revealed, the fruit's presence aroused the entire audience, as not only was it a Logia, but it also previously belonged to the son of the Pirate King.

As per Doflamingo's prediction, Luffy could not stand the idea of his brother's former powers open for just anyone to take, and participated in the tournament. Since he already had the Gomu Gomu no Mi, he could not eat it himself and offered it to Franky, who turned down the offer because he wanted to retain his ability to swim.

Besides Luffy, representatives from many kingdoms joined the tournament to claim the fruit as it would give them a small shift in military power. Others wished to claim it for their own reasons such as Cavendish, who wanted revenge on the Worst Generation, and Rebecca, who wanted it to kill Doflamingo. Bellamy seemed to be the only one with no interest in it, as the only prize he desired was to become a top subordinate in Doflamingo's crew, though he did not need the fruit anyway since he already possessed the Bane Bane no Mi. Also, Bartolomeo's reason for getting the fruit is to give it to his idol Luffy, as he already possesses a Devil Fruit which is capable of creating invisible walls. Sabo wants to get the fruit to inherit Ace's will.

Once Sabo destroyed the Colosseum platform, he then grabbed the fruit from off the Fighting Fish's back, and ate it seconds later, becoming the new wielder of Ace's powers. True to his word of inheriting Ace's will, the first thing Sabo did after eating it was use his brother's signature move, the "Hiken". Diamante was angered by this, as he never intended for anyone outside of the Donquixote Family to win the fruit.

After Sabo stops Jesus Burgess from killing Luffy for the Gomu Gomu no Mi and revealing that he was the Lucy who won and ate the Mera Mera no Mi, Burgess targets him for the Logia that he originally wanted.

Anime and Manga Differences

 * In the manga, Ace introduces the Mera Mera no Mi after he already took care of the Marines headed by Smoker. In the anime he is seen confronting Smoker a bit longer.
 * In the anime, the Mera Mera no Mi also granted the user the power to light objects on fire from a distance, as demonstrated when Ace lit one of Sanji's cigarettes, although it was never shown again.

Trivia

 * The Mera Mera no Mi is the only known Devil Fruit that has been eaten twice in the series.
 * The idea of a Devil Fruit that would allow someone to use fire was first brought up when Morgan explained what Devil Fruits are.
 * Its powers were first foreshadowed when Ace visited a town on Drum Island, when it did not snow on that day, although it did for the whole Drum Island Arc.
 * It is the only known Logia Fruit that was not eaten by an antagonist, as Ace and Sabo are both Luffy's brothers.
 * This is the second Devil Fruit to be shown coming back into circulation after its user's death, the other being Smiley's Devil Fruit — the Sara Sara no Mi, Model: Axolotl. However, this is the first Devil Fruit whose possessor was human.
 * The color of Ace's fire changed over the course of the series, originally appearing red-orange to a more yellow orange color. However, when Sabo first used the fruit in the anime, its shade appeared red-orange again.