I'm pretty sure we have been looking at the larger meta story of AoA in the wrong light. It all started when I was doing another run through the main story, and I noticed something peculiar while in the profane capitol-
That chalice/container that holds the profane flame down outside of Yhorm's boss fight? It looks just like the chalice Father Ariandelle holds. When I realized this, it was like taking a red pill- AoA story tells us what the profane flame is. It's been right in front of our faces the whole time, and even hints to a much larger, grander plot in Dark Souls in general.
The story in AoA is opposite and parallel to Pontiff Sulyvahn's entire plotline in our world. Right down to the characters, everything is similar, yet opposite. I think in order to understand my theory, we should run through the story so you can see every parallel:
Lady Elfriede was the leader of the sable church (the pontiff, basically). She lost everything in trying to usurp the flame and end the rotting age of fire, and became an ashen one. Because she knew loss and was forlorn, she was drawn into the painting. Once there, Elfriede assumed a new identity, and quickly (forcefully) became the matriarch of the painted world. She imprisoned the half-dragon Painter Girl, and she teamed up with Father Ariandelle, and had him use his blood to appease the flame growing below the world, and prolong the rotting painted world. This flame apparently is similar to our own first flame, perhaps a counterpart, and is capable of kindling Lady Friede.
Pontiff Sulyvahn was a young sorcerer in the painted world who had lost nothing. Because he was not familiar to loss, he left the painted world and eventually came to Irithyll (where I assume the painted world was being kept at the time). There, he assumed a new identity and saw that our world was stuck in a rotting age like his old painted world. He rose through the ranks, and became a pontiff in the way of white church. Eventually Sulyvahn found a flame in the profane capitol far below Anor Londo, similar to the painted world. But unlike the flame in the painted world, this was a flame of the abyss, triggered by the relatives of a certain oracle. These relatives were warped into the Monstrosity of Sins that now roam the Profaned Capitol. Unlike Lady Friede, Suly embraced this flame and plans on using it to burn the rot from our world (the burning ambition that took hold).
Sulyvahn had the way of white embrace the deep (the deep being of the dark, similar to the profane flame), and teamed up with Aldrich to oppose the gods who keep our world in a state of rot. He imprisoned a half-dragon girl, and together with Aldrich overthrew the gods and Sulyvahn assumed leadership.
Sulyvahn and Friede are counterparts of each other, both playing out the same story but with opposite motives. Their stories end with parallels as well- they are both defeated by the Ashen One, ending Suly's attempt to purge the corrupt gods keeping our world in a state of rot, and ending Friede's reign keeping the painted world in a state rot.
So with all of this laid before us, here are some theories that I have:
The Monstrosity of Sin's in the profaned capitol are relatives of a "certain oracle". The only oracle EVER in the Dark Souls series is Alsanna, the daughter of Manus. It would make sense, since these monstrosity's have many features similar to Manus, and are weak to anti-abyss weaponry (Farron GS and WK GS). From these MoS, their "curse" triggered the Profane Flame. They also look a lot like the ogre's in DS2, and DS2 being the game Alsanna comes from… I think you get the idea.
I think the profane flame serves a similar purpose to the flame in the painted world, as it is intended to "burn away the rot". The rot in our main world coming from the unending age of fire, the age of the gods. It'd make sense the profane flame was a flame of the abyss. It also makes sense why it only burns away flesh and corrupts the user of the flame. The flame in the painted world is probably similar to the first flame of the gods, which explains why it can kindle Lady Friede and burn away the rot of the painted world.
It'd also make sense why Yhorm decided to link the first flame when the Profane Flame consumed the profane capitol- he tried to fight "fire with fire"- that being the flames of the abyss vs. the rotting flame of the gods (opposites), which didn't turn out too well for the profaned capitol. It was like trying to fight fire with gasoline.
Here are some more parallels:
The painter girl in AoA serves as a counterpart to Yorshka. They are opposites in every regard. Yorshka is naive and ignorant, and really doesn't know what her purpose is. The painted girl does not know her name, and is stalwart and resolute in painting a new world for men. They both have "relatives", Yorshka's being her brother Gwyndolin, chief god of Anor Londo who wishes to keep our world in a rotting age of fire, and the painted world has "uncle" Gael, a lowly slave knight who seeks Ashen Ones to help burn the rot of his world away.
Even the rot of each world appears to be opposites. The painted world's rot is apparently related to the dark (perhaps the pigment used to make the painted world?), as the corvians who consume the rot turn into flies (similar to how the dark turn men into beasts) and they drop human pine resin, while the rot of our main world comes from the First Flame, the fire of the gods.
Even the flames to burn the rot away are opposites, the profane flame of our world is of the abyss, and "profane" flame in Father Ariandelle's world burns away the "dark" rot and can kindle Lady Friede into Lord of Cinder mode.
So what do you think? Everything in here can tie to something said or seen in game, and I'm not really a big fan of making large, sweeping plot assumptions without too much evidence. I hope you enjoyed reading this, and I really hope this gives you a sort of new appreciation to the story of Ashes of Ariandelle, because I think through it's parallels we can get answers to some unanswered questions.
Here is one more parallel that I will leave you with- Suly and Friede's stories are like dueling serpents. Suly is a guy we all assumed was a major douche nozzle, just a no-good cunt who deceived all of Anor Londo. Lady Friede is former proponent of ending the age of fire, our rot, but eventually changed her mind and embraced it, and was embraced by Father Ariandelle and some Corvians.
It makes a lot more sense if you look at Suly and Friede in the same light as Kaathe and Frampt…