Basically, I think the Gorosei are likely to be named after Saturn, Jupiter, Mars, Venus, and Mercury- the first 5 planets to be discovered. We don’t have much to go off of, but I reread all of their appearances so far and looked into their “assumed” references to get a feel for their personalities. I’ll explain my reasoning for which I think is which, in order of how strong my reasoning is.
Saint Saturn
– Saturn is the god of time, known in Greek as Kronos. Some translations differ, but this is likely how it applies in One Piece
– Often mentions time or the passage of time to some extent, notably just before his name was revealed.
– Most facial hair, always seen with a cane, generally looks the “oldest”.
Saint Mars
– Mars is the god of war, known in Greek as Ares
– Carries a sword in all appearances, heavily theorized to be a cursed blade- Kitetsu
– Often discusses military strategy, is the most assertive and decisive, often pushes the Gorosei past indecision. Generally acts more like a general than a politician
– Looks and poses similar to Ghandi, but seems to act the complete opposite- simply carrying a weapon is in conflict with his legacy. War, rather than peace.
Saint Mercury
-Mercury: god of wealth and commerce, known in Greek as Hermes
– Seems most interested in “maintaining the status quo”, doesn’t like acting in response to individuals.
– His head mark is a reference to Mikhail Gorbachev, known for dissolving the soviet union in sake of economic reform. If my assumed God of War is a contrast to Ghandi, Gorbachev would likely be contrasted in Mercury
Saint Venus
– Venus is the god of love and fertility, known in Greek as Aphrodite.
– Often “says it like it is”, usually reframes what the Gorosei’s objective truly is in clearer/fewer words.
– Youngest, tallest, neatest facial hair, popped Collar w/ exposed chest, generally the most “conventionally attractive”
Saint Jupiter
– Jupiter: God of the sky and king of the gods, known in Greek as Zeus
– Process of elimination, mostly. I don’t have strong reasoning here.
– Theorized to be designed after Itagaki Taisuke, who from what I can tell is an activist leader and founder of prominent political movements in Japan.
– Least confrontational or assertive, most visibly shocked or worried about new developments whenever we see the Gorosei react. Could be done to oppose the confident, imposing nature expected of a “leader”.
Theory by Yeardmee (https://www.reddit.com/user/Yeardmee)
