A word in the speech of the Lords that can awaken another Lords or kill those who aren't hosts.
Spiritual parasites that reside within humans. When awoken, they take over the body, giving it powers to warp the reality itself. Each one of them rules over one aspect of reality. They are the ones who bring the end of the world.
Four years, during which humanity was exterminated to a point they can be almost called extinct.
A few highest layers of The Pit where the deadly sunlight can reach. Every layer is covered with an endless sea of sand. While they are called The Surface, they are still underground.
Giant, insect-like, often capable of flight creatures that come from outside of The Pit. Which should be impossible.