The feeling of something being trapped and trying to get out is really scary. The crack in the slab is like a barrier that might not hold for long. For example, in some stories, there are strange sounds of scratching as if whatever is under is desperately trying to break free. This builds a lot of tension and fear. Also, the idea that the slab might be the only thing separating our normal world from something very abnormal and dangerous is quite frightening.
One cracked slab horror story is about an old, abandoned house. The basement had a cracked slab. People started hearing strange noises coming from beneath it. When they finally got the courage to look, a noxious smell came out. They saw some strange marks on the cracked part as if something was trying to break through.
The unknown is a very terrifying element. For example, in a story where there are strange noises in the dark but you don't know what's making them. It scares people because our imagination runs wild.
The unknown. In 'la horror stories', often it's the things that are not clearly seen or understood that are the most terrifying. For example, a strange noise in the dark. You don't know what's making it.
The sense of betrayal. Cops are supposed to protect, so when they turn into something evil or are part of the horror, it's really scary. For example, when a cop starts to hunt down his own colleagues.
The isolation. In vanguard horror stories, the vanguard is often far from any form of help. For example, if they are in a remote battlefield area or an uncharted territory. There's no one to call for backup easily.
The transformation of familiar things into something menacing is a terrifying aspect. For example, a Kender might enter a meadow that they thought was safe but then find that the flowers start to move on their own and have sharp teeth, or the trees start to reach out with their branches like arms. This distortion of the familiar into the macabre makes for a truly terrifying Kender horror story.
The sudden equipment failure is really terrifying. For example, if your rope snaps or a crucial piece of gear breaks, you're in immediate danger. It can happen without warning and leave you helpless.
The idea of something lurking inside the saveya, waiting for the next victim. It could be a malevolent spirit or some sort of inhuman creature. The darkness within the saveya also plays a role. When it's pitch - black, our imagination runs wild, and we start to fear the worst.
The suddenness of death. The blade of the guillotine falls so quickly, leaving no time for the victim to fully comprehend what's happening. It's that instant transition from life to death that's truly terrifying.
The isolation. When you're in a snowstorm, you can be cut off from the rest of the world. No one can reach you and you can't reach anyone. It's like you're alone in a frozen hell.