I had to read it twice, this article is mind-bending. It reminds me of the buddhist idea of a mirror with no reflection - how can there be nothing reflected in a mirror? Only if there is nothing. It also reminds me of the quote "If you want to make an apple pie from scratch you must first create the universe."
I think this is an okay idea, but it needs a lot of expanding on.
What did the people do to deserve that hell? How did you arrive as a guest? How is it possible to leave? Can you leave if you are a guest? Why is it even possible for there to be guests? What is that thing in the sky? Why does it generate the dreams of being trapped?
I quite like this submission, I imagine it as an excerpt in a game from a book or overheard in a classroom. I am particularly partial to the idea of the shadow having effects in the shadow realm which then translate to effects in the material realm. Solid work.
The plot hooks are very good, and I really like this take on the forbidden text. I also think the introduction really sets the tone for the piece and probably describes as much in itself as all of the non-italic text. I am unsure if this is the place to discuss it, but it is a worthwhile question that could be explored through gameplay:
If stripped of all that a person values, what really is left?
Obviously there are those that have to survive the verses, how do they do it? What makes their mental state different?
I very nice look at a minor god / large being that answered any questions I had about him as it went. His usefulness is limited since, as is stated, he can only exist in darkness. Perhaps he has caught something, some trinket or person, and is running around the world with them in constant darkness. Would make for an interesting quest, always being in shadow and facing creatures of the night.