If I remember right, I saw you comment on a post where you said you were inspired by the Pitioss Ruins Theory at the beginning of your worldcrafting. Since it's used as a curse, I was wondering what exactly it is for your worlds. Hell? The afterlife? A cursed place no fool who enters come back out of and is therefore likely a gateway to one of the two?
Time to get meta and delve into the creation myth! >:D
I rambled about parts of this before in some really old posts here, here, here and here. (Some things have changed a bit over time, but the important parts are still the same.)
Three dieties are important: Chaos, Eos and Etro. (I also smooshed a bit of Versus XIII into this XD)
In the beginning there were only the siblings Chaos and Etro until Etro grew lonely and created a planet and all life on it. And she did so by taking a part of herself and her sibling and forcing order upon it. And because Chaos is part of Destruction and Etro is Death (but also Sleep and Magic and All Things Hidden) everything that lives is destined to eventually die.
Since it wasn’t an element neither Chaos nor Etro had reign over, there was no light.
Until there came a lone wandering Goddess without a name. She saw what Etro had done and fell in love with her creation. The nameless Goddess asked to stay and gave her light as a gift. She took her right eye to make the sun and out of her left she carved the moon. In reverence the humans named her and the planet Eos. (Patron of all who Wander, who reigns over Light and Healing and the Dawn.)
The creation of the sun and moon is also when the Astrals were made. Ifrit, Ramuh and Titan out of sunlight, Shiva and Leviathan out of moonlight and Bahamut out of the blood Eos cried when she ripped out her eyes.
(Carbuncle is far older and one of the Astrals of Etro along with Doomtrain.)
Anyway, back when Etro made the world, not all of the Chaos was used and that Chaos became Pitioss. A place buried deep within the earth, forgotten by most. There was no Scourge. Yet.
Then, Eos did something that was the greatest betrayal she could do in the eyes of Bahamut. She fell in love with a human and gave birth to his children. As punishment Bahamut took Eos and imprisoned her into Pitioss.
There, the Chaos came into contact with Eos and started to slowly consume her light. This act began to transform the Chaos into something else. Something hungry for the warmth of life and light. Chaos became Scourge. And slowly, bit by bit, it was killing Eos.
Up on the surface, Ifrit was furious. He had been the closest to their mother and came to abhor Bahamut for what he had done. This is what caused the Astral War which ended with the destruction of Solheim, when Ifrit, desperate to get to his mother, called down a meteor to distract Titan and burned down the old Empire. His Empire. He rode Doomtrain down into Pitioss and reached Eos, who by then was already close to death.
She died when Ifrit carried her to the surface.
Ifrit, badly wounded from the War and further weakened by his journey into Pitioss, turned his own body into a pyre for his mother (which became Mt. Ravatogh and burns to this day).
With this act something happened that no one had expected. The Chaos - now the Scourge - that had burried itself into Eos’s body, was released onto the world in the form of a poisonous smoke. It spread fast.
Bahamut, desperate to salvage the situation, and preserve the last flickers of his mother’s light, ripped out her heart, which turned to crystal.
This crystal Bahamut gifted to a family line who was curiosly powerful in all things magic.
In the end, for humanity Pitioss is the origin of all things evil. They may not know that this is where the Scourge comes from, but collective memory has it that this place none but the Gods have ever seen, is where all the pain and suffering on their planet comes from.