Background & User
The Hayai Hayai no Mi (English: Fast Fast Fruit) is a Paramecia Type Devil Fruit that allows it's user, Dan the Calamity, to move their body parts faster than lightning. Dan can also control air by moving his body fast. While moving fast, the user hits harder.
Using Other Materials
The user can hold other materials and make the material move faster. For example, using this ability with a sword made the sword a lot sharper.
In terms of Design, it has a star and three bananas, with a red stem.