[@Dusty]Will have a look and get back to you along with the others.

[@Terminal]Interesting points. A lot of it is in the name of what has actually happened in this world, 'purgatory', which is just a temporary existence of (sometimes relative) torment and suffering. It all depends on who and what that inhabits this purgatory. But seeing as it is temporary, one can assume that other planes of existence, timelines, and variations of the very same purgatory exists.

The description of dawn coming only hours before dusk does indicate that daylight is short, but also implies that the long nights are filled with terror. So your comparison with Dark Souls' function is valid, even though the causes for it might be different. The beauty of Dark Souls, Bloodborne, or whichever of those games that you reference, is the immense room for personal interpretation. But you are correct in that daylight will offer much needed respite.

I'd suggest that Seekers are limited to this purgatory, and the alternate variations of it through certain paintings. So, cracks in the mortar, so to speak, could definitely occur in works of art and other places of significance that allows for traversal between variations of this purgatory. If all of this is true, one might consider and wonder what the Herald of Light actually is.

But again, the vague nature of these things is what keeps the mystery and to some extent the horror interesting.