The Taiyo Taiyo no Mi is a Logia-type Devil Fruit that allows the user to create, manipulate, and even become solar energy. It was eaten by Date Goku Better known as Goldbeard, Captain of the Goldbeard Pirates.
Strengths and Weaknesses
The main strength is that, with this fruit, the user can create, shape and manipulate all aspects of a sun to their will, starting from its immense heat, luminosity, mass/gravitational field, magnetic field, raw nuclear energy and reaction, etc. More specific effects include solar winds/flares, geomagnetic storms, sunspot reactions causation, UV emissions, and plant growth promotion.
A possible weakness of this fruit is a Devil Fruit that is of Lunar Manipulation, the opposite of solar manipulation. Other than that, the standard Devil Fruit weaknesses apply.