Sekai Sekai no Mi

The Planet Planet Fruit (世界世界の実 Sekai Sekai no Mi) is a Paramecia class Devil Fruit; bestowing upon its user the ability to create various planetoids out of anything they touch, making the user a Planet Human (世界人間 Sekai Ningen.) So far, no known user of the Planet Planet Fruit has been revealed as of yet.

Strengths and Weaknesses
The main ability the Planet Planet Fruit seems to possess, is that by coming into contact with any inanimate object, animal or person, the user can transform them into a spherical planet. The planets can come in a variety of shapes, from being no bigger than a basketball to the size of buildings. The transformation process also seems to be reversible, allowing the user to deconstruct their own planets at will. Upon doing so, it's revealed no lasting damage or injury comes to anyone or anything transformed into a planet.

After a planetoid is created, the user can carry them around as material goods for an indefinite amount of time, or even pass them along to others. As a side effect of the fruit's power, the user of the Planet Planet Fruit seems to be capable of controlling their planets' motion and movement through an ability similar to telekinesis. This allows them to keep their various planets at their side without the use of their hands or the worry of taking up too much space. However, the range at which this pseudo-telekinesis works appears very limited, as planets will drop out of the air if they're too far apart from the user. This telekinetic ability also holds offensive capability. With it, the user can launch planets like projectiles towards their opponent, or hide behind them like a shield for defensive support. Planets can even be used as a form of support, by transporting the user and anyone or anything of their choosing across indefinite distances; making this a valuable form of avoiding drowning, due to the common weakness to the ocean which all Devil Fruit users share. When used in tandem, multiple planets of various sizes and materials can be made an effective form of combat.

The Planet Planet Fruit also grants its user the ability to manipulate anything happening upon the planetoids' surface. As a planet, the effects of evolution can occur over time if life is introduced to the planet. The planet's life forms however, cannot be seen by the naked eye, as they're too small in relative proportion to the planet's diameter; much like the One Piece world or our own real planet, Earth. Despite this, they do exist independently of the user or the world beyond their own. They can be manipulated by the Devil Fruit's user though, as the user can control how quickly the evolution process works, by either speeding up evolution or slowing it down to a standstill. Combined with the variety of materials a planet can be crafted from, such as metal, wood, stone, flame or living beings, the user can create a vast, wildly diverse collection of flora and fauna. In addition, the user can freely summon any living plant or animal found amongst their planets and use them to the user's liking. This too can be used for the benefit of the user's allies. As a result, the Planet Planet Fruit provides a wide array of resources for its user to take advantage of at any given moment.

Despite the control the user has over the life found on their planets, the user cannot transport himself or anyone else onto the planets' surface; keeping their powers limited to only the planets themselves. And likewise, as with all other Devil Fruit users, the user suffers from standard Devil Fruit weaknesses.

Trivia

 * The Planet Planet Fruit's ability to control the various planets' ecosystems was inspired by the main power of the Garden Garden Fruit.