The Flame Flame Fruit, also known as the Mera Mera no Mi, is a Logia type Devil Fruit, deemed to be one of the most powerful in the world of One Piece. The power of this Devil Fruit allows the user to control and turn into flames at will, making it an extremely destructive fruit to have at your disposal.
This Devil Fruit was first eaten by Portgas D. Ace and after his death, his brother, Sabo ate it. Although it is a powerful Logia, there are quite a few Devil Fruits stronger than Ace's Mera Mera no Mi.
10 Stronger: Magu Magu no Mi
The Magu Magu no Mi is a Logia type of Devil Fruit and its powers are wielded by none other than the current Fleet Admiral of the Navy, Akainu. This fruit allows him to turn into magma and also control it at will.
According to Akainu himself, it is powerful enough to burn through fire, meaning this Devil Fruit is superior to the Flame Flame Fruit of Portgas D. Ace.
9 Weaker: Hie Hie no Mi
Also known as the Chilly Chilly Fruit, this Devil Fruit was eaten by none other than Kuzan, a former Navy Admiral. Its powers allow him to control and turn into ice at will.
It is easy to see that fire has quite a big advantage over ice and thus, the Mera Mera no Mi is superior to it in every way.
8 Stronger: Pika Pika no Mi
The Pika Pika no Mi, or the Glint Glint Fruit, was eaten by Navy Admiral Kizaru and its powers allow him to transform into light and manipulate it freely.
The Pika Pika no Mi is one of the most powerful Devil Fruits in the series, and worthy of competing with the Flame Flame Fruit. It is also a Logia type of Devil Fruit, meaning it is extremely rare.
7 Weaker: Yuki Yuki no Mi
Eaten by Monet, the Yuki Yuki no Mi or the Snow Snow Fruit granted her the ability to turn into snow at will. Thanks to them, she could rage blizzards at will. Monet was strong enough to fight against a Navy Captain, meaning her powers were no joke.
While the Yuki Yuki no Mi is strong, it doesn't really stand any chance against the Mera Mera no Mi, simply because the latter has an affinity over it.
6 Stronger: Tori Tori no Mi, Model: Phoenix
Eaten by the former First Division Commander of the Whitebeard Pirates, Marco the Phoenix, this Devil Fruit is quite powerful and it grants him the ability to transform into the Mythical creature Phoenix at will.
It boosts the physical attributes of the user considerably, but most importantly, it grants them the ability to heal infinitely. Even Kizaru had trouble keeping up with Marco's healing.
5 Weaker: Kage Kage no Mi
Eaten by the former Shichibukai Gecko Moria, the Kage Kage no Mi allows him to control shadows at will. He can also steal shadows from people and give them to corpses to turn them into zombies, or feed on them to get stronger himself.
While the possibilities of using this Devil Fruit seem limitless, it is definitely weaker than the Mera Mera no Mi, simply because the destructive capabilities of the latter are too much for it to beat.
4 Stronger: Yami Yami no Mi
Another Logia type of Devil Fruit, the Yami Yami no Mi allows the user to control darkness at will. It was eaten by Marshall D. Teach, also known as Blackbeard, a former member of the Whitebeard Pirates.
This Devil Fruit has the power to suck in anything, including light itself. According to Blackbeard, it is so powerful that it sucks in his intangibility too. However, in return, it lets the user nullify the Devil Fruit powers of others.
3 Weaker: Zou Zou no Mi, Model: Mammoth
Eaten by one of the three right-hand men of Kaido, Jack the Drought, this Devil Fruit belongs to the Ancient Zoan class and it grants him the ability to transform into a Mammoth at will.
The stamina and raw power that the fruit grants is incredible and it let him fight the Mink tribe for 5 days and nights continuously. It goes without saying that the Zou Zou no Mi is powerful, however, the Mera Mera no Mi is far more dangerous.
2 Stronger: Gura Gura no Mi
One of the strongest known Devil Fruits in the world of One Piece, the Gura Gura no Mi was eaten by Edward Newgate, also known as the Whitebeard. Currently, this power belongs to Blackbeard, one of the Four Emperors of the Sea.
The Gura Gura no Mi allows the user to summon quakes at will. It can split apart oceans and sink islands within a matter of seconds. Undoubtedly, it is much stronger than the Mera Mera no Mi.
1 Weaker: Zushi Zushi no Mi
Zushi Zushi no Mi, also known as the Thump Thump Fruit, was eaten by the current Navy Admiral Fujitora. It grants him the power to manipulate Gravity at will and even summon meteorites at will.
While this Devil Fruit is powerful, it doesn't really work well against the Mera Mera no Mi, as seen when Sabo was easily able to avoid the Raging Tiger by turning into fire. It definitely isn't weak by any means, however, the Mera Mera no Mi is much better.