Darklit Cities

The collective of settlements within the Pitch Black Forest. Midlanders have a very hierarchical system stemming from the fact that only a limited number of people could gain access to powerful fire magic. Meanwhile, every Cotd has a much higher baseline of planar affinity as a result of it stemming from the constantly leaking Darklight, resulting in a much more even power distribution.
Generally, the near indefinite lifespan of citizens results in a heavy focus on individual achievement and self-improvement.
When pressed from the outside, the Darklit Cities are extremely quick to form a united front, but quickly re-dissolve into squabbling once the threat passes. Inter-city sabotage is relatively common.
One of the biggest issues in the cities' culture is writing: there is no darklight equivalent of pen and paper. As a result, a lot of culture has shifted towards oral forms, reinforced by having firsthand accounts for histories in most cases. In areas where light cannot exist without being suffocated, most important writing is done in etched metal plates or clay tablets. Other areas make use of candles and the like, even during the day.

Expansion

The Pitch Black Forest is constantly slowly expanding laterally, creating an cracking effect similar to paint on an expanding balloon. This tends to have damaging effects on larger scale architecture, resulting in a preference for tall and/or untethered structures to minimize drift. Strong soul claims can help anchor given sections of the land and potentially halt the effect entirely within an area. This is part of why several Shrouded rule cities- they have dominion over the centers of the cities, allowing others to build around them. This expansion is also part of why Cotd generally do not appreciate architecture. Even if no war or monster reaches the structure, it will fall apart within decades to centuries anyway.
To continue the balloon analogy, it's important to note that the world is being stretched thin- at some point in the future, the 'balloon' could theoretically burst. This would result in a series of events reminiscent of the Scar's creation, although there is no guarantee of somebody being able to stop it at that. The 'plateau' effect of the Darkness linkage means that nothing too bad can leak through. At the same time, the key factor which stops attracting demons to the base of the cliff in the first place is the fact that Cotd are generally empty or otherwise lacking in soul energy, making them hard to sense. Incidentally, this adds another layer of discomfort to outsiders. Not only are they in absolute darkness, there are fleeting feelings of being watched by things they cannot hope to understand. Shrouded, for all their dark and terrible power, are still within the scope of human comprehension- by necessity, given that they were human not that long ago (in the grand scheme of things). Demons may have been human once, but so long ago as to forget everything.

Cities

There are 3 main cities with patron Shrouded. Numerous smaller settlements exist within the Pitch Black Forest, but have been considered minor powers at most throughout history. The Darklit Cities' populations are pretty small by non-Cotd standards, typically numbering around several thousand.
Shadow spirits known as puppeteers also have a place in Cotd society. Their appearances vary greatly, being that they interact with the world by taking control of pre-existing objects. Skeletons, ents, and golems of animated stone are common forms for these entities to take. They are generally regarded as second-class citizens or even animals depending on local views due to their (typically) minimal intellects. Their very psychology tends to support this, as a puppeteer's primal need appears to be to 'be part of a story' in the same way that humans require food and drink. Should a puppeteer ever truly be unsatisfied, it can simply discorporate- or so the people justify their actions. These spirits tend to be more common in smaller settlements. A significant portion of them simply wander the borders of the forest as animated corpses.
In general though, they are found adjacent to civilization as opposed to within it. The smaller and more isolated a settlement is, the higher its number of puppeteers- this is generally believed to be because the puppeteers have a hard time managing their 'story' when several thousand 'viewers' are involved, instead preferring areas where they can account for every 'character'. Some also think that this is why puppeteers rarely stray outside the Pitch Black Forest without being summoned- immortal actors result in less need to rewrite the script.