One Piece Mural Theory
Sun God: Nika- Monkey D. Luffy
Earth God: ?-Imu
Forest God: Nidhogg- Loki
Sea God: Zaza- ?
•The First World:
-Within the earth, there was fire.
-Mankind succumbed to greed and touched the forbidden sun.
-The enslaved prayed, and the Sun God appeared.
-The Earth God raged, and with it's serpent of Hellfire shrouded the world in death and darkness.
-And they will never meet.
•The Second World
-Within the emptiness, there was breath.
-The Forest God tamed demons, and the sun spread the fires of war.
-Those of the half moon dreamed.
-Those of the moon dreamed.
-Man killed the sun and became god.
-And the Sea God stormed.
-And they will never meet.
•The Third World
-Within the chaos, there was a void.
-The inconvenient remnants recall the promised day and hear the voice of the broken moon.
-The Sun God dances and laughs, guiding the world to its end.
-The Sun returns and brings forth a new morning.
-And they will surely meet.
The First World- Ancient Times
The Second World- The Void Century
The Third World- Present Day
-(Within the Earth, there was fire)= People harnessed the Mother Flame, perhaps found beneath the ground.
-(Mankind succumbed to greed, and touched the sun)= Something mankind did that brought the creation of Devil Fruits. Born from human desire.
-(The enslaved prayed, and the Sun God appeared)= The desire for liberation caused the Nika Fruit to appear.
-(The Earth God raged, and with it's serpent of Hellfire shrouded the world in death and darkness)=The ones who were enslaving most likely ancient ancestors of the Celestial Dragons angered by the idea of freedom desired a power to combat Nika, and the Earth God fruit appeared likely the power of Imu. It's power of confinement controlling a deadly ancient beast.
-(And they will never meet)= I think this refers to all of the Gods meeting. Through the course of the war they failed to meet before the death of any of them.
-(Within the emptiness there was breath)= After the Celestial Dragons won, they snuffed out the idea of liberation once more, until Joyboy appears.
-(The Forest God tamed the demons, and the sun spread fires of war)=The Forest God being Nidhogg, the great Dragon and a fruit born from the Adam trees, not an enemy of Joyboy, but a rival. With an ideal that made it so they didn't work together. While Joyboy united the the races spreading the idea of Liberation once more.
-(Those of the Moon dreamed)
-(Those of the half moon dreamed)= Referencing the people who joined the fight against the oppressor. Giants, Ancient Giants, Mermaids, Fishman, Dwarves, The Longarm Tribe, The Longleg Tribe, Minks, Lunarians, Humans with the Will of D. and the Kozuki Clan. Although the Birkans are in the Mural with the Ark it looks as if they fled to one of the Moons.
-(Man killed the sun and became god)= The oppressors were also human or the same race that originally brought the Devil Fruits. And in their act of defeating Nika, they deemed themselves Gods or gained something to make them believe they were gods hence the Celestial Dragons calling themselves Gods.
-(And the Sea God stormed)= Due to the Death of Joyboy, Zaza's ally. She created a way to hinder the Earth God at this time Imu by making it so any Devil Fruit eater would sink into the sea.
-(And they will never meet)= I think this refers to all of the Gods meeting. Through the course of the war they failed to meet before the death of any of them.
-(Within the chaos, there was a void)=Through the tumultuous time i.e. The Great Pirate era, modern day mankind is brought up to speed on the Void Century.
-(The inconvenient remnants recall the promised day and hear the voice of the broken moon)= The ones who survived since the Void Century and been waiting for Luffy aka Joyboy's Successor. Zunesha, The Sea Kings from Fishman Island and Emet who all hear the voice of Joyboy within Luffy. The Moon representative of the people on Joyboy's side.
-(The Sun God dances and laughs guiding the world to it's end)=Nika finally prevails against the Earth God
-(The Sun returns and brings forth a new morning)= Possibly referring to the end of the Powers that spurred on Devil Fruits or the creation of Devil Fruits as God's return to their respective domains.
-(And they will surely meet)= Zaza, Nika, Nidhogg and the Earth God all finally meet in one location.
The Moons- The Symbol in the mural which represents the people fighting on Joyboy's side, Also found in the Kozuki Clan symbol. I think depicts the Moon and it's 8 Phases, as well as the Earth and it's 8 moons. The Orrey in Ohara showed 6 Moons. Which I believe speaks of the age they're in. The 1st World could be referencing the 1st Moon and the 1st Moon to vanish from the sky. The Second world being the 2nd moon to vanish.