One Piece’s vast collection of Devil Fruits include both the conveniently useful and the awfully useless. Plenty of Devil Fruits grant superhuman abilities that assist their wielders in their day-to-day endeavors. These convenient Devil Fruits not only prove valuable during combat but they sometimes also provide all sorts of auxiliary support during peace.
Granted that not having offensive capabilities does not necessarily entail a Devil Fruit’s uselessness. While it’s true that the very best of Devil Fruits cover various other aspects besides battle, these exist in the minorities. A considerable chunk of Devil Fruits is unsuitable for battle; some would be outright useless if not for a single redeeming quality or two.
10 Garb-Garb Fruit (Kin’emon)
Though it has its uses, Kin’emon’s Fuku Fuku no Mi has little to no firepower. From what fans have seen, the Devil Fruit’s only use is to transform unassuming objects (e.g rocks) into full-fledged outfits.
Espionage works and spying missions are the only times this Devil Fruit will get to shine. Any other time and its uses could easily be replaced by the nearest clothing store.
9 Jacket-Jacket Fruit (Kelly Funk)
While it would appear as a useful Devil Fruit at a first glance, what it offers is actually less than what it suggests. The ability to become a jacket; what a useless ability this one is. The Devil Fruit’s end might be impressive, but the means are just too contradicting.
By becoming a jacket, the user will be able to take control of their wearer. The catch is, jackets can only chill in the hanger while waiting to be consensually worn.
8 Spin-Spin Fruit (Buffalo)
This Devil Fruit’s only strong point is its ability to produce a flying human; it fails in nearly every other aspect. And it’s not like its flying capabilities are all that impressive. The fruit only grants the ability to conjure propellers, the user will have to figure out the rest.
Buffalo proved that this Devil Fruit’s weaknesses are more thorough than one would expect. A force with the strength to propel oneself in the air is not early enough to seal the deal to most battles in the New World.
7 Swim-Swim Fruit (Senior Pink)
This Devil Fruit really doesn’t bother to hide its inconsistencies. Swimming in everything but water? What’s the actual point! If it allowed the user to phase through solid objects, then it would indeed be formidable.
But it’s not that easy; Senior Pink has to actually swim in order to move. Of course, he also has to come back for air every now and then -- a significant drawback, to say the least.
6 Kilo-Kilo Fruit (Miss Valentine)
Kilo-Kilo Fruit allows one to alter their weight without actually changing their body structure. The minimum weight is 1 kg and the max weight is 10,000 kg. When used correctly, one would be able to deliver solid hits to the enemy.
But the Devil Fruit’s numerous weaknesses deter any enthusiasm to try and grasp the ins and outs of it. Furthermore, a changed weight does not entail an altered density (i.e. the only way to make this Devil Fruit work is to rely on gravity).
5 Art-Art Fruit (Giolla)
At the very least, this Devil Fruit is true to its name, although even that is debatable -- art is subjective after all. The problem is, even when the target is transformed into ‘art’, they’ll not be incapacitated.
When Giolla unleashed her not-so-explosive art all over Thousand Sunny Go, all the present Straw Hats were hit by it. Brook, who was supposed to be art-ified, still managed to knock her off with minimum effort, and this begs the question: is there any actual use?
4 Calm-Calm Fruit (Donquixote Rosinante)
Calm-Calm Fruit, or Nagi Nagi no Mi, is also one of these Devil Fruit with annoyingly specific usabilities. All it does is shutting off the noises within the bubble it creates. Yes, it could prove helpful in stealth and infiltrating missions, but that’s the extent of it.
That being said, though, if the Devil Fruit’s ‘silence bubble’ was much larger in size, its uses would’ve been more numerous.
3 Blamenco’s Devil Fruit
Blamenco and his Devil Fruit still remain unexplored to date. Even though the man in question is a mighty yonko commander, he did not get the treatment of his more popular counterparts. Fans still know next to nothing about him.
His Devil Fruit is one that allows him to store objects inside his body. As far as fans are concerned, it’s nothing more than a slightly inflated pocket.
2 Mark-Mark Fruit (Vander Decken IX)
Mark-Mark Fruit allows the user to mark any individual touched with their hands as a sniping target -- which defeats the entire purpose of sniping. If the user touched any other person with the same hand, their initial target will be overwritten.
Moreso, this Devil Fruit is greatly limited by the number of hands. On normal occasions, one can only have two active targets at a time.
1 Slip-Slip Fruit (Alvida)
Prior to the age of Haki, this Devil Fruit’s performance was more than notable. It grants the user a nearly impregnable defense against blunt damage. Any damage that comes the user’s way would simply slip off.
That said, that was during a time where Haki was scarce. As it currently stands, any competent character with slightly above average Armament Haki will be able to shake off Alvida’s defenses.