The Kami Kami no Mi, literally meaning "God God fruit" is the very first devil fruit in existence created by an alien race far away, lost, dead, wiped out, and forgotten. It was eaten Rasuto, the literal creator of the One Piece Earth and a "God" who goes around testing the might of other races, those races deemed too weak lose their lives and their planet. His name means last, which references that he is the last of his kind. It has no class. It's class is not unknown, it simply doesn't have one it is neither all 3 or none at all, it simply is without.
The Kami Kami no me is a no class devil fruit that grants the Rasuto control over the very forces of creation and destruction. It was created by the alien race Fasutoraito, literally meaning "The First Light". Rasuto is able to create anything out of nothing he desires, he cannot however create life forms but this does not stop him from creating the basic ingredients and conditions. It is the very power of creation that he used to create the planet that the story of one Piece takes place. It also lets the user erase anything from existence with a jet black beam made of oblivion. Surviving the beam is impossible as the beam is not a matter of sheer power, but the fact that it is made of the energies of the very concept oblivion, destruction, and nothingness itself. Nothing is capable of surviving even being immortal and absolutely unable to die it for just as all things have an existence, they have a nonexistence as well, this beam brings out the nonexistence within that which is hit. It also grants control and manipulation over anything he creates however this only applies to what he directly creates, any "offspring" born from his creation cannot be manipulated by him. Rasuto is also in a state of omnilock. His powers can not be used against him, stolen, overloaded, or erased, nor can he be harmed in any way by anything even attacks with infinite levels of infinite power nor even conceptual ones. Why? Because that is why, Rasuto needs no reason to be above such attacks because that is just how his abilities work. They don't need nor have a reason, much like an Omnipotent being. however he is only Omnipoptent in the regard that he is compelltely unable to harmed or fettered unless he wills it. Rasutos abilities themselves are somewhat flawed though it would be difficult to tell the difference. the Kami Kami no Mi also makes the user enlightened and the user becomes aware of many things outside of the users existence, such to the point that Rasuto was even capable of realizing that there were different Omniverses, he is even aware of the universe that contains our very earth, yes the same earth that I am making this page on, that you and I and everyone on the planet, the "our" universe is in. The fruit also grants control over every element, particularly darkness and light, powers commonly associated with destruction and creation, in addition to the ability to transform into anything/anyone in existence. Finally Rasuto is capable of transforming from his original mortal form to his God Form which grants complete omnilock to everything and he becomes the very embodiment of destruction and creation.