One Piece: 7 Devil Fruits that are useless in combat

In One Piece, Devil Fruits bestow permanent superhuman powers to those who consume them, though at the price of their ability to swim. These extraordinary powers are as varied as they are fantastical, allowing users to alter their own bodies and those of their opponents, generate substances, manipulate the environment, transform into animals, and even wield control over natural elements.

With their wide variety of peculiar abilities, each with distinct strengths and weaknesses, Devil Fruits bring a thrilling unpredictability to fights. This enriches One Piece’s combat dynamics with variety. The hundreds of different Devil Fruit powers offer infinite new possibilities, which ensures that no two battles are alike in the series.

Granted, Haki has now become the deciding factor in most One Piece fights, but Devil Fruits continue to play a prominent role in the franchise’s combat scenes. Nearly all Devil Fruits, no matter how bizarre their abilities, can be useful in battle, though their effectiveness depends on the user’s mastery, creativity, and overall fighting skills. However, a few Devil Fruits offer very limited combat utility due to their lack of offensive potential or sheer impracticality.

Disclaimer: This article contains major spoilers from the One Piece manga up to chapter 1150.

7 One Piece Devil Fruits that aren't suitable for direct combat

1) Time-Time Fruit

Toki using the Time-Time Fruit in One Piece (Image via Toei Animation)

The Time-Time Fruit endows its user with the extraordinary ability to send themselves or others years or even decades forward in time, though this offers no application in battle. Unlike the fearsome time-manipulating powers wielded by some of the most dangerous Stands from JoJo’s Bizarre Adventure, this Devil Fruit can’t stop or reverse time, just travel forward in time.

At best, the Time-Time Fruit can be used to escape from dangerous situations by moving to a future far enough that the threat would be long past. In One Piece, this Devil Fruit was wielded by Toki, the wife of Kozuki Oden, and the mother of Momonosuke and Hiyori.

Born about 830 years before the present narration, Toki used the Time-Time Fruit to go forward in time more than once, until fate led her to Oden. After her husband’s death, Toki used her Devil Fruit ability to send Momonosuke and some of the Red Scabbards twenty years into the future. She then perished in the fire of Oden’s castle, and with her passing, the Time-Time Fruit returned into circulation, respawning elsewhere in the world.

2) Cook-Cook Fruit

Streusen using the Cook-Cook Fruit in One Piece (Image via Toei Animation)

The Cook-Cook Fruit is owned by Streusen, the co-founder of the Big Mom Pirates alongside Charlotte Linlin. Now an elderly man, Streusen is the executive chef of the aforementioned crew. This role certainly befits him, considering that the Cook-Cook Fruit allows him to convert any object into edible food.

It should be mentioned that the food created with the Cook-Cook Fruit is nourishing, but lacks flavor and doesn’t taste good. With this Devil Fruit, the user can perform absurd actions, such as instantly transforming an entire castle into food.

That said, while Capone Bege speculated that Streusen could be a capable fighter, the Cook-Cook Fruit never demonstrated any actual combat technique. It was only used to transform objects into food to feed the user and other people. However, the ability to turn objects into food could render weapons inoffensive.

3) Heal-Heal Fruit

Mansherry using the Heal-Heal Fruit in One Piece (Image via Toei Animation)

As its name implies, the Heal-Heal Fruit allows the user to heal any injured living being, including themselves, with no limits, except they can’t recreate a destroyed body or body part out of nothing. Users perform the healing by pouring their bodily fluids on the target, immediately restoring them.

This Devil Fruit can also be used to repair damaged objects to their original condition, though in this case, the effect will come at the cost of the user’s lifespan being shortened. It remains unknown whether the Heal-Heal Fruit can cure diseases. The Heal-Heal Fruit has no offensive potential, so it is pointless in combat. However, it can still heal the user and their allies.

In One Piece, the Heal-Heal Fruit is wielded by Mansherry, a cute and kindhearted dwarf with a funny tsundere attitude toward Leo. As the daughter of Gancho, the king of the Tontatta Kingdom, Mansherry is the princess of the same reign. She mainly manifests her Devil Fruit powers in the form of tears that heal anything they touch.

4) Grow-Grow Fruit

Biblo using the Grow-Grow Fruit in One Piece (Image via Shueisha)

The Grow-Grow was recently introduced in One Piece, first appearing during the ongoing Elbaph Arc. This Devil Fruit allows the user to enlarge inanimate objects, making them gigantic. The enlarged objects can be reverted to their original size at the user’s will.

The wielder of this Devil Fruit is Biblo, an owl serving as the chief librarian of Elbaph’s Owl Library. Biblo primarily uses the Grow-Grow Fruit to enlarge the human-sized books stored in the library – including the invaluable books salvaged from Ohara – so that they would be accessible to the towering Giants.

5) Jacket-Jacket Fruit

Kelly Funk using the Jacket-Jacket Fruit (Image via Toei Animation)

The Jacket-Jacket Fruit transforms the user into a grotesque human-skin jacket capable of enveloping and controlling another person’s body to exploit their physical abilities. The jacket adapts to fit any host, regardless of any size difference between the user and the wearer.

One Piece unveiled Kelly Funk as the user of this Devil Fruit, as he employed it in the Corrida Colosseum to merge with his brother Bobby, thereby accessing the latter’s abnormal physical strength and body durability. That said, the Jacket-Jacket Fruit likely hinges on finding a willing host, as it’s uncertain whether the user can force other people to wear the jacket.

In any case, a skilled opponent may dodge the attempt, or even repel the control in some way, perhaps with Haki strong enough. Also, the user’s strength will be tied to the host’s body, making this Devil Fruit a risky gamble as possessing a weaker host would diminish the user’s power. So, the Jacket-Jacket Fruit is inherently useless in combat, relying entirely on the right circumstances to benefit the user.

6) Human-Human Fruit

Chopper using the Human-Human Fruit in One Piece (Image via Toei Animation)

The Human-Human Fruit, a one-of-a-kind Zoan Devil Fruit, is the key to Tony Tony Chopper’s transformation from a simple reindeer to the cherished doctor of the Straw Hat Pirates and a fan-favorite character in the series. This Devil Fruit allows the user to transform into a human, so when consumed by an animal, it bestows the typical characteristics of a human, including advanced intelligence, knowledge acquisition, the ability to speak, use tools, and perform bipedal movement.

While this Devil Fruit profoundly changed Chopper’s life, it would offer no value to an eventual human user, granting them traits that humans already possess by their very nature. Most Zoan Devil Fruits amplify physical attributes like speed, strength, and durability, or provide unique features such as wings for flight or razor-sharp claws to attack, depending on the animal they are based on, but the Human-Human Fruit offers no significant combat edge.

For human users, the transformation into a human would be entirely useless, while for animal users, it wouldn’t be necessarily an improvement. A small, vulnerable creature might gain power from transforming into a human, but a mighty predator could actually find its natural combat prowess diminished. As for Chopper, his ingenuity in developing the Rumble Balls was essential to making the Human-Human Fruit combat-effective.

7) Garb-Garb Fruit

Kinemon using the Garb-Garb Fruit in One Piece (Image via Toei Animation)

The Garb-Garb is literally useless in battle, granting the user the ability to transform things like stones and leaves into clothing tailored depending on the user’s imagination and knowledge. While this power may come in handy when the user needs specific garments, for instance, to disguise themselves in order to infiltrate enemy gatherings, it lacks any utility in direct combat.

In One Piece, the Garb-Garb Fruit is owned by Kinemon, one of the Red Scabbards, and perhaps Momonosuke’s most devoted retainer. During the Wano Arc, Kinemon used his Devil Fruit ability to disguise the members of the Ninja-Pirate-Mink-Samurai Alliance, enabling them to blend among the Beasts Pirates and infiltrate Onigashima.

To change their attire, individuals passed beneath a gate topped with a leaf-shaped banner, with their clothes being magically transformed in an instant. Funnily enough, Kinemon considers his Devil Fruit powers to be the result of some special ninja jutsu.

Though a decently strong fighter in his own right, Kinemon stood no chance against Kaido, even when fighting him alongside his fellow Scabbards. Not that much would change, but Kinemon didn’t even try to use the Garb-Garb Fruit in the desperate battle against Kaido, knowing full well that this Devil Fruit, only suitable for changing garments, would offer him no help in combat.