- In the aforementioned Greek mythology, that would be Tartarus, a Primordial God who was the ruler of the abyss. Tartarus (I highly recommend reading this link) was also the name of the said abyss – a dark place located even deeper than the Underworld that served as a dungeon of torment and suffering for the wicked and as the prison for the Titans. It was essentially Hell for Hell.
- In Egyptian mythology, [Nu (“Watery One”)](https://en.wikipedia.org/wiki/Nu\_(mythology)#:\~:text=Nu%20(%22Watery%20One%22)%20or%20Nun%20(%22The%20Inert,which%20the%20creator%20sun%20god%20Ra%20arose.) or Nun is the personification of the primordial watery abyss which existed at the time of creation and from which the creator sun god Ra arose. In the beginning the universe only consisted of a great chaotic cosmic ocean, and the ocean itself was referred to as Nu.
So, "Nu", the Watery one in Egyptian Mythology, can be viewed as the "personification" of the Abyss that is "Tartarus" in Greek Mythology.
This fits One Piece perfectly: "Nu" is the ruler of the "Abyss" Tartarus... or Tar D. Eris
Not getting into the "Eris is Imu theories", but, here's WorstGenHQ for that: https://x.com/WorstGenHQ/status/1976014682524926286
Cerberus guards the gates of the Underworld, of which Tartarus is a part of; the worst part (Impel Down connection?).
Shamrock is clearly one of Imu's favored Agents, being sent to deal with Loki and Elbaph, a country which conquered the New World, and then back to the Marijoa after it was attacked. Since many believe Imu cannot directly leave the Flower Room, merely their Shadow (KOZUKI MORIA WILL DEFEAT IMU-SAMA, YOU HEARD IT HERE FIRST. IT'S SCISSORING TIME, JUST LIKE MY LESBIAN TRIGGER ANIME, KILL LA KILL), and the Gorosei being Giant Demon dudes is a secret, I believe Imu needed their strongest non-Gorosei to show up to help: Shamrock.
Being capable of killing Loki with a single thrust, when Gunko barely damaged Loki after how many attacks, is proof Shamrock's attack power is very dangerous.
What do we know about the Man Marked by Flames?
Black ship with whirlpools
Government man most likely
Has 4th Road Ponyglyph, the one missing from Fish-Man Island.
What interests me most, is that we're supposed to believe the man has a burn scar, but, no one has mentioned any other features: how is it that people know he has a scar, if they don't know any of his other physical features?
https://fictionhorizon.com/one-piece-who-is-the-man-with-the-burn-scars/
Well, as for the identity of this character, we have nothing to add. He was initially mentioned as 火ヒノ傷キズ (Hinokizu) in the series, which was later as simply ヒノキズ in katakana, but the phrase actually means “Fire Wound,” i.e., “Burn Scar,” which is the official English translation as well. This means that it could very well be that Hinokizu is not the character’s real name, i.e., that it is just a nickname based on his most pronounced physical trait, as we do know that the person known as Hinokizu does have a scar somewhere on his body.
What if we were looking at this the wrong way, the whole time? The Man Marked by Flames, "Burn Scar", or "Fire Wound", is named as such... because the people he fights are scarred by his flames.
The Flames of Hell.
The Flames of Tartarus', and Imu's, Guard Dog: Cerberus.
Tartarus is the Greek Hell, based off Egyptian Mythology, that houses the most fearsome monsters in the world. What are Imu and the Gorosei? The most fearsome monsters in the world.
Gunko and Shamrock dress in black cloaks: I believe they also have a black ship.
Gunko's Arrow Fruit is what causes the Whirpools that sink the ships.
Shamrock was the God's Knight sent to retrieve Myosgard from Fish-Man Island, after his accident there. A God's Knight would be sent in this situation, as we know from Akainu that God's Knights handle internal matters like that. Myosgard randomly inviting Otohime to the Holy Land must have been a BIG DEAL at the time, and, since Shamrock has been seen associating with Giants, he would be a good liaison here. Shamrock has been shown to visit Harald's Grave in Elbaph, implying Shamrock was fond of Harald, and more open minded about countries like Elbaph than Garling. If Shamrock honestly enjoys exploring (like Garling, who was very interested in God Valley's history), it would make sense Shamrock went exploring Fish-Man Island. He's powerful enough that no one would be able to stop him, there.
So, Shamrock found the Road Poneglyph, and, just as Shanks' serves as a barrier to Laugh Tale, Shamrock became a barrier himself, sailing around with the Road Poneglyph to keep it from being stolen. In the event someone tries to, Gunko would sink the Poneglyph into the sea with her Fruit, leaving it to be reclaimed by the WG later.
If this theory is correct, it would mean Luffy would have to defeat Shanks' brother, in order to gain the last Road Poneglyph needed to reach Laugh Tale. This lets Luffy fights a Shanks' level enemy, to reach Laugh Tale, without fighting Shanks himself.
It also entirely possible Shanks challenges Shamrock, his own brother, for the Poneglyph.
Either way, I believe Shamrock is Fire Wound, the Man Marked by Flames, and he has been tasked with keeping the 4th Road Poneglyph safe, to make up for the failures of his brother, Shanks.
Shamrock and Shanks are a twisted parallel of Lola and Chiffon.
Imu is like Linlin: even though Doffy wanted to return to Marijoa, he was refused entry. Since Shanks abandoned Imu, Shamrock DISGUSTS Imu, inherently. However, after retrieving the 4th Road Poneglyph, Shamrock was promoted to a high rank, and fell into Imu's good favor.
Garling despise Shanks, because Shanks' status as a pirate serving under Gol D. Roger brought shame to the Figarland family that still lingers. Hence Garling's intro, decrying those who protect scum.
Shanks chose protecting the weak, over being an all powerful God, a Celestial Dragon, and brought shame to his family.
Shamrock's true mission from Imu?
To kill his brother... the Yonkou, Red Haired Shanks, now that he has set his sights on Laugh Tale
The easiest way for Shamrock to lure Shanks in?
Monkey D. Luffy
Fire Wound... is coming to snuff out Shanks' protege.
The Flames of Hell, have spread to Elbaph, and Shamrock's sword burns with the desire to end the Great Age of Pirates.
