Hito Hito No Mi, Model: Nika is a mythical zoan devil fruit which is currently possessed by Monkey D Luffy. It enables the user to get the powers of Sun God Nika (A.K.A Warrior of Liberation) and it gives the user a rubber like body.
It's powers is limited by the user's imagination. It can turn everything it touches to have/be very rubbery or elastic properties. It can also produce any elements like lightning, fire, and ice if the user wants to. It can also make the user to be bigger or smaller.
It is also The One and Only Natural Enemy of Lightning Especially against The Goro-Goro no Mi which is A Logia Type Devil Fruit Which Gives the User the ability to Control, Manipulate and Create Lightning.
Even the fruit is limited by imagination so it can also have weaknesses. Its rubber powers have a limit. If the user's body is stretched too long or too much it will start to rip off just like what happened to Toto Land Arc.
Fun Fact: The Hito-Hito no Mi Model: Nika was known as the “Gomu Gomu no Mi” until we find out in the current story that he actually ate the mythical zoan Hito-Hito no mi Model: Nika fruit.