Long ago in the past, there existed people who lived atop the Red Line that could generate flames from their body. After certain events occurred, these people were ‘lost in the mists of time’ and currently the only member of this race shown is King the Wildfire. Taking into account what we know about this race, we can extrapolate a few pieces of information about this race: they weren’t on friendly terms with the Tenryuubito and due to likely not wanting to give up their home, they were targeted and brought to the edge of extinction. Few may have escaped by abandoning their home but they lost to what is now the World Government. Marijoa may also have been the location of this races homeland. Like other shadows the World Government wishes to hide, they buried knowledge of such a race in the darkness of time, omitting them from the history they wish known.
If there is such a connection to the World Government, I also wonder if there is a connection between this race and the people of the Ancient Civilisation such as the Skypieans, Shandorians, and Birkans. The wings King possesses may indicate that there is. The people who existed atop the Red Line could be a different race that belonged to the Ancient Civilisation or a hybrid of Ancient Civilisation races. What seems certain is that the wings King possesses isn’t the result of his Devil Fruit but an inherit feature derived from his blood which is a key feature of the Ancient Civilisation races. It will be interesting learn how Hitetsu also fits into all of this given that he has a pair of wings too.
One other fascinating revelation about King’s race is the ability they have to ‘burst into flames’. Where else have we seen someone do something similar? Obviously through Fire Fist Ace and Sabo. Is there some connection between that race and the Mera Mera no Mi? How exactly are Devil Fruits born and where do they derive their powers from? Could there be more to the Mera Mera no Mi and this race? If SMILE Fruits are anything to go on, if a certain animal DNA was used in the SMILE Fruit, that animal or animals will dictate what the person consuming the SMILE Fruit will transform into. Do natural Devil Fruits function in the same manner? When exposed to an element, DNA or substance while growing, do they take on such characteristics? Was the Mera Mera no Mi born from absorbing the DNA of someone who could control flames? At this point, one can’t say with any certainty. It’s possible though.
Curiously, where was the user of the Mera Mera no Mi last seen? Well it was atop the Red Line in Marijoa. After the events of the Levely/Reverie, Sabo’s status remains a mystery but we do know that something considerable occurred concerning him in Marijoa. A person that could burst into flames being present atop the Red Line where a race of people who could burst into flames existed. Such commonalities may not be coincidence and may lead into a deeper mystery surrounding the Void Century and the actions of the World Government. Could Sabo have come across more people that belong to this race in Marijoa? King’s history could very well lead into the story unfolding around where Sabo currently is.
In the past I had theorised that Yamato’s mother could have belonged to the same race as King and I wonder if that will still come to pass. Yamato not possessing wings could be the result of being a hybrid between the race Kaido and his mother are. If Oda-sensei wants to give Yamato the ability to use flames, he could incorporate it through Yamato’s racials. The flame-like aesthetic of Yamato’s Okuchi no Makami form could be the result of his blood if not from the Mythical Devil Fruit. To differentiate other flame uses, Oda-sensei could combine Yamato’s ice powers with his flames and produce a blue or ice flame which is what Yamato’s Namuji Glacier Fang appears to be.
King may have been captured by the Marines and at some point was rescued by Kaido. If Yamato’s mother belonged to the same race, it wouldn’t be that surprising considering King is a subordinate of Kaido’s and if Kaido encountered one member of that race, he could have also encountered a second member. The suit King wears may be necessary after the experiments conducted on him.
I wonder if Robin would have any insight in the history of this race or even be aware of their existence. Surely with the knowledge that Ohara once possessed, they would have been some information on a race that existed atop the Red Line in the past. If race existed in the Void Century as part of the Ancient Civilisation, it would be even more likely that Ohara had researched on it.
This may be nothing but such a revelation makes me wonder if Monet’s story of adjusting her body to replace her limbs with wings, talons and a tail have a connection to the race that belonged atop the Red Line in the past. When her research of Astronomy, Biology and Birds and fascination for the Pirate King title are taken into consideration, they could be a deeper story in play with her character. Her past of existing in a terrible environment with Sugar before Doflamingo recruited them could also be leveraged.