This sun god is worshiped in Skypiea, Elbaf and probably Fishman Island too.

But along with God of the Sun, in Skypiea three more gods were mentioned – God of the Rain, God of the Forest and God of the Earth.

So Luffy has the Sun God devil fruit. That leave us with three more Gods.

In worldwide Folklore, Storms are often depicted as a sign of destruction or is known as a foreshadow for something terrible to come. I theorise that the Rain God is the Warrior od Festruction and will have the ability of Elemental Manipulation. A person with the Rain God Devil Fruit would be able to use and manipulate every natural element except water, basically giving him the ability to use almost every logia ability. Wind, Lightning, Ice, Fire, Magma, Snow, Sand, Wood, Gas, smoke and possibly even more natural elements. The Person I think already has this fruit is Monkey D. Dragon.

The Earth God is the Warrior of Authority and will have the ability of Authority Manipulation. This is the Authority Manipulation the Earth God may have:1-Territory/Terrain Manipulation (The user can create, shape, and manipulate territories under their jurisdiction. They have the the ability to mergeide, shrink/enlarge and otherwise warp territories and what is in them. Basically, reality warping a territory they control)2-Subordinate Manipulation (The power to subjugate others by dominating them and their ability to be sentient and independent beings. To put it in simpler terms, the ability to submit and control people.)The Person I think already has this fruit is Imu.World Government has thousands of Islands under their territory, The Marines are the world’s largest Military organisation, and they works under the World Government, and Imu with the Earth God Fruit, can control and manipulate them all.I believe Imu, during the Void Century, after Joy Boy’s fall,claimed territory over a large section of the One-Piece World. Imu manipulated that territory and created what is known as the Red Line.

I theorise that the Forest God is the Warrior of Creation and will have the ability of Life Manipulation. A person with the Forest God Devil Fruit will be able to manipulate any living organism (Animal/Sea creature/insect/plant/people).Other abilities include:1- age manipulation2- form manipulation (shape-shifting)3- Life absorption and redirection (taking life energy from a living organism and using it for healing or strengthening another)4- Regeneration5- Zoolingualism and Botanical Communication (ability to talk to animals and plants).6- Biological Transmutation (the ability to combine organisms to create a new life-form).The Person I think might already has this fruit is Loki, the Prince of Elbaf.