A person can only eat a single
The Yami Yami no Mi allows the user to absorb Devil Fruit powers from dead users and assimilate it into their own body, without causing their bodies to explode. It is a "unique" fruit, even for a Logia. Blackbeard somehow caused the Gura Gura no Mi to grow after Whitebeard died, and then consumed it.
Can Luffy take second devil fruits or not? No. At present the only person who has, somehow, managed to acquire two devils fruit powers is Blackbeard, and no one knows how he did that. Normally if someone eats a second devils fruit, it'll poison them and they'll die.
Actually not just 1, he can eat 3 devil fruits. Yes.
Blackbeard is the only character in One Piece with two Devil Fruits. How did he do it? Marshall D. Teach, better known by his epithet, is arguably the most dangerous living pirate in One Piece.
Zoro set out on his journey to becoming the greatest swordsman in the world by defeating Dracule Mihawk, the man who currently sits on the stone. Over the years, he has come a long way and become one of the strongest pirates on the seas. Zoro has attained terrific strength, but he does not rely on a Devil Fruit at all.
The Hito Hito no Mi, Model: Nika was first revealed to the fans in the very first chapter of the story. Luffy ate the fruit thinking it was dessert and gained the power of rubber ever since. The fruit was actually in possession of Shanks and according to his crew, they stole it from an enemy ship.
Sanji hated Absalom even more because he ate the Suke Suke no Mi. However, though this was the only Devil Fruit that Sanji was ever interested in, he lost interest in the fruit after his fight with Absalom, deciding that he shall just have to peek on women anyway without it.
While Sanji does not have a Devil Fruit, if you were to ever eat one, there are certain ones that would fit him perfectly.
Magu Magu no Mi. Admiral Akainu's devil fruit Magu Magu no Mi is the ultimate weapon for absolute destruction. It is the most powerful raw power (even better than fire) in the One Piece world. This devil fruit allows the user to create and control magma at their will, along with turning themselves into magma.
The fruit was a treasure sought by the World Government for over 800 years, until it was stolen by Shanks and his crew in recent history. It was then accidentally eaten twelve years ago by the series' protagonist, Monkey D. Luffy.
As it turns out, Luffy's Devil Fruit wasn't the Gum-Gum Fruit at all but instead it was a wholly different kind of ability as his power is officially that of Nika, the Sun God thanks to the true identity of his fruit.
Shanks is the only member confirmed to have not eaten a Devil Fruit. Shanks is the only member who is not an Admiral of a Fleet. Shanks is the only member of the original Four Emperors to not be a member of the Rocks Pirates.
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.
Imu is the sovereign of the World Government and arguably the strongest character in One Piece. Imu seems to have access to some kind of ability/weapon that allowed him to destroy the Kingdom of Lulusia in an instant.
1 Charlotte Linlin – Age 6
Along with the semla that was given to her, Linlin also accidentally ate all her friends and Mother Carmel, who held the power of the Soru Soru no Mi, thus becoming the user of this fruit on the day she turned 6.
She ate the Love-Love Fruit, which allows her to turn her opponents into stone. In order for this power to work, the target must first have feelings of attraction towards the user. Nami is beautiful, and it has been shown that many characters find her attractive, just like Hancock.
The Daishou Daishou no Mi is a Paramecia type Devil Fruit eaten by Nefertari Vivi a month after the Straw Hats departed from Arabasta.
Luffy's rubber attributes are a result of him eating a devil fruit called the Gum-Gum Fruit Granting him a rubber-like body, his powers make him immune to electric attacks and most blunt forces, but he is susceptible to attacks made with a sharp object or weapon (eg. sword, spear).
Luffy ended up awakening his Devil Fruit, which turned out to be a Mythical Zoan Devil Fruit based on a legendary character, giving him a new form and set of skills in an unexpected turn of events.
It was revealed to the fans that his Devil Fruit was actually the Hito Hito no Mi, Model: Nika, and went by a different name to hide its true powers. In his awakened state, Luffy became much stronger than he ever was before and his level of strength grew to a point where even Kaido was fearful of his powers.
During Sanji's cooking battle in a Loguetown Arc filler episode, it was mentioned that some fish species that should not exist in the East Blue were found due to ocean currents, which made Sanji certain that the All Blue exists.
Thankfully, Oda answered this question in an SBS. He gave his opinion on the devil fruits that they would possess, and his choice for Usopp was the Poke Poke no Mi, which is a paramecia-type devil fruit. It was eaten by Blamenco, and it allows him to create pockets everywhere on his body.
In the manga and anime series "One Piece," Roronoa Zoro, one of the main characters, is shown to have lost his left eye.