Conditions for Acquiring Devil Fruit Abilities
When a Human Eats It
Law and Buggy swallowed their fruits whole, while Luffy and Sabo bit into theirs — all of these are cases where the fruit was eaten with its skin and became a Devil Fruit user.
However, Kaku managed to become a user after peeling and eating a banana-like fruit. This tells us that only the flesh of the fruit needs to be consumed.
But how much of the fruit actually needs to be eaten?
Kalifa used a knife and fork to cut the fruit into small pieces and ate only a single bite.
This shows us that taking even one bite right at the start is enough to become a Devil Fruit user.
So where exactly does “eating” begin and end?
We’ve seen several cases where objects became Devil Fruit users. But what does it even mean for an object to eat a fruit?
Guns Have a “Mouth”
I tried to think about what stage of the eating process is actually required.
- Putting it in the mouth
- Chewing it
- Swallowing it
From Buggy and Law’s cases, we can tell that chewing isn’t necessary. So is the condition either putting it in the mouth or swallowing it?
However, in the scenes with Kaku and Kalifa, the Devil Fruit spiral pattern is already shown before they swallow.
Come to think of it, Devil Fruits taste incredibly bad. I wonder if becoming a user still works if you spit it out because it’s too disgusting after putting it in your mouth?
Based on this, the act of putting it in the mouth seems to be what matters.
With that in mind, a gun has a muzzle — which is a kind of “mouth” — so it’s possible for a Devil Fruit to be placed inside it.
Swords Also Have a “Mouth”
What about Funkfreed’s case then? Looking up the names of a sword’s parts, I found that the opening of the scabbard is called the “koikuchi” (carp’s mouth) in Japanese. And a sword has a blade — which is also teeth.
That’s a much closer name to a human mouth than a gun muzzle.
The Gel’s Case
I couldn’t find any “mouth” at all for the toxic gel. Perhaps Caesar, who could freely manipulate the poisonous gas, shaped the gel into a mouth-form so that the Devil Fruit recognized it as having been “eaten.” However, this theory assumes that the Zoan-type Devil Fruit has will — which is a premise in itself.
Where Devil Fruit Power Resides
Not the Heart, Not the Mind
When Law used his ability to remove Smoker’s heart, Tashigi’s consciousness was placed into Smoker’s body — but the Moku Moku power stayed with Smoker’s body, and Tashigi’s mind couldn’t control it.
So the location where the Devil Fruit ability resides is not the “heart” or the “mind” — it’s “somewhere in the physical body.”
Not Muscles, Not Organs Either
Brook’s case may be special, but if the same conditions apply to other abilities, then since Brook — who has no skin, flesh, brain, eyeballs, or blood — still has his ability, it must reside in either his bones, his hair, or perhaps the cerebrospinal fluid remaining in his spine.
Though it seems easier to just say it’s in the “DNA” — the one thing they all have in common. Or perhaps the Yomi Yomi no Mi alone resides in the soul.
Does It Reside in the Blood? — Lineage Factors
The word “lineage” suggests something passed down through a family line from ancestors. So it seems that in cases like Vander Decken, the Devil Fruit power can be inherited from parent to child.
Since it’s called a “lineage factor,” it likely resides in the blood. The trigger for inheritance is probably the parent’s death, and if there are siblings, the oldest bloodline would likely be chosen.
Blood and sperm can both be called “DNA.”
Recognizing the Host’s Death
According to a grunt from the Donquixote Family, “when a Devil Fruit user dies, a new fruit with the same ability awakens somewhere in the world.”
This was shown right after Smiley died and became Shinokuni on Punk Hazard.
At that time, it seemed to move into the nearest available fruit.
Thinking about it more, it raises an interesting question. When Smiley — originally a toxic gel that had “eaten” a Devil Fruit and gained a will — died: the gel could split into smaller parts, and burning one portion didn’t count as the whole dying. But when a chemical reaction from drugs turned it into a state it couldn’t return from, that was when “death” was recognized.
From this, we can hypothesize that for objects with a residing Devil Fruit, “death” is defined as the moment it can no longer return to its original state.
For a sword, that would be when the blade breaks. For a gun, when it’s cut completely in two.
And, perhaps limited to Zoan types, it seems Devil Fruits don’t just have will — they have life itself. The reason carnivorous Zoan types exhibit increased ferocity is likely because the Devil’s will is layered on top.
Methods of Stealing Devil Fruit Abilities
The shadows stolen by Moria’s ability retained the skills of the original person’s body. That’s why Luffy, who had a swordsman’s shadow inserted into him, could use swordsmanship.
However, Oars, who had Luffy’s shadow inserted, didn’t gain the Gum-Gum ability. It seems Devil Fruit powers don’t reside in shadows.
This suggests that the ability residing somewhere in the body lingers inside it for a while even after the user’s death.
Blackbeard’s Method
- Use “Dark Vortex” or “Blackhole” on a recently deceased person to suck out their Devil Fruit ability
- Direct the extracted power toward a prepared fruit using “Repel”
- A new Devil Fruit is born
- Eat it
Blackbeard’s case will eventually be depicted in the story, so I’ll leave it at a brief hypothesis for now.
Big Mom’s Case
In Big Mom’s case, could it be an application of “lineage factors”? Mother Carmel, known by the alias “the Mountain Witch who sold orphans,” was the previous user of the Soru Soru no Mi.
At a birthday celebration, Big Mom was presented with a tower of her beloved semla, and with tears of joy blinding her vision, she devoured everything in frenzied excitement, eating up everything within arm’s reach.
When Big Mom was done eating, everyone around her was gone and almost no furniture remained — but Big Mom’s bite marks were still there.
In other words, Big Mom had eaten Mother Carmel, the orphans, and everything else.
After that, she gained Mother Carmel’s “Soru Soru” ability.
Let’s analyze this incident focusing solely on the conditions for ability transfer:
- The Devil’s power resides in DNA
- Between parent and child who share DNA, the ability can sometimes be inherited
- The Devil’s power recognizes the death of its user and changes hosts
In other words: Big Mom ate Carmel, taking the user’s blood into her body, and when Carmel died, the ability transferred.
Momonosuke and Kaido’s Case
A hypothesis about why the artificial Devil Fruit Vegapunk created is considered a failure.
“Kaido cannot die.”
Kaido’s introduction showed him jumping off a Sky Island to commit suicide. Let’s look back at what was said about Kaido at the time:
- 7 defeats as a pirate, captured by the Navy or enemies 18 times
- Over 1,000 torture sessions
- 40 execution orders
- Hung but the chains snapped
- Placed on a guillotine but the blade shattered
- Skewered but the spears broke
- Sank 9 massive prison ships as a result
- Nobody could kill him
So Kaido cannot “die” — the very trigger for Devil Fruit power transfer?
Momonosuke’s Completion When Kaido Dies
Vegapunk, having given up on Kaido’s death, called the artificial Devil Fruit he created from Kaido a “failure.”
If Kaido were to die, Vegapunk’s artificial Devil Fruit would be completed.
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