I was thinking about Monkey D. Dragon’s tattoos and how we know only a few other characters with abstract tattoos, most notably the Shandians of Sky Island.
So I was considering what could the significance of his tattoo be, and I believe it looks similar to the Aztec symbol relating to the five suns in connection to Quetzalcoatl mythos.
This myth coincidentally involves an androgynous god (I attribute this connection to Ivankov being with the Revolutionaries) who has a child for each cardinal direction- in this case we know a son in East Blue. Each Sun represents an era of time and based on the prospects and prophecies for our boy Luffy he seems to represent the dawn of a new age in the world of One Piece.
The myth of Quetzalcoatl derives from this myth in that the arrival of this figure signals the end of that era (many believed Cortez to be Quetzalcoatl because of the knowledge, destruction and power he brought to the New World) which is also fitting for the most wanted criminal in the world- the Revolutionary leader.
Quetzalcoatl is a feathered serpent that could be the “western dragon” people say would fit the series since it already clearly has an eastern dragon with Kaido. Similarly Kaido’s tattoos represent his dragon attributes so it wouldn’t be far fetched to think that Dragon’s tattoos likewise represent something about his character.
The Shandians definitely have their inspiration from the Mayan/Aztec and Incan empires that existed in the Americas pre-colonization, and the powers of Quetzalcoatl connects the skies to the earth. This can be interpreted as Dragon has done something for the Skypeians in the past and gained some knowledge from it (ancient history like we have seen Enel do since his defeat) or that he will facilitate the connection of “heaven” (the Tenryubito) and “earth” (the general world).
Quetzalcoatl also has the power of the wind, and is the bringer of rain and thunder, which has already been closely associated with Dragon, seen when he arrives in Loguetown during a sudden storm as well as when he arrives near Goa Kingdom on his ship seemingly whisking in from the wind.
His ship likewise depicts an actual serpentine dragon that could be seen as the feathered Quetzalcoatl.
*Theory by perpetualWSOL