Isolation. If Dassam Falls is in a remote area, the feeling of being alone and cut off from help can heighten the horror. People getting lost in the wilderness around the falls and encountering unknown terrors would be a common element in such a horror story.
The power of the falls itself can be a factor. The strong current could be seen as something that can 'swallow' people, and in a horror story, it might be depicted as having a malevolent will.
I'm not really sure of the specific Dassam Falls horror story. But generally, in horror stories related to waterfalls, there could be tales of strange disappearances. Maybe people who ventured too close to the falls at Dassam mysteriously vanished, and locals might claim it was the work of some malevolent spirit lurking in the misty waters.
Ghosts could be a possible element. In 1928, superstition was still quite prevalent, and a horror story might involve the apparition of a vengeful spirit.
One possible element is a haunted location. The princess might live in a spooky castle filled with secret passages and rooms where strange things happen. Another element could be a malevolent force like a demon or a powerful sorcerer who targets the princess. For example, the sorcerer might use dark magic to make the princess see terrifying visions.
Ghosts could be an element. In many horror stories, ghosts play a major role. They can haunt a place, like an old building in Navsari, and cause fear among the people living nearby.
One possible element could be the use of his unique musical sounds as a trigger for the horror. His music often has intense and somewhat otherworldly beats that could be associated with something sinister.
The Detroit Horror Story may contain elements such as the isolation of certain neighborhoods. These areas, cut off from the rest of the city, can feel like a world of their own, full of mystery and danger. The presence of graffiti - covered walls and broken streetlights can add to the spooky atmosphere. There could also be elements related to the city's history of racial tensions, which could manifest in stories of hauntings or vengeful spirits.
The waiter himself could be a key element. He might have a past he doesn't remember, which is somehow related to the horror. For example, he could have been involved in a murder at the restaurant in a past life, and now the spirits are coming back to haunt him. Also, the customers could be strange, like they are not really human but some sort of otherworldly beings just pretending to be normal diners.
Malfunction could be one. Like when it doesn't stop vibrating or changes its pattern unexpectedly.
One possible element could be a creepy old mansion. It might be abandoned and full of dark corners where strange things happen.
One possible element is the sudden and terrifying hallucinations. People on bad 'ecstasy' might see grotesque monsters or distorted versions of people around them.