Perhaps the scariest aspect is the psychological impact it has on the people in the story. For example, the feeling of being watched by the doll all the time, and the paranoia that builds up as strange things keep happening. The characters in the story start to question their own sanity, which is a very scary thought. In addition, if the doll has some sort of connection to a dark past or an evil entity, that also adds to the scariness. It's like there's an unseen and malevolent force lurking behind the seemingly innocent - looking doll.
In the 'lucy doll scary story', one of the scariest parts is when the doll starts to interact with the environment in a malicious way. Say, it makes other objects in the room move or break. It gives the impression that the doll has a will of its own and is out to cause harm. Also, if there are any signs that the doll is somehow 'alive', like if it blinks or makes noises that seem like it's trying to communicate in a creepy way, that would be extremely frightening.
For me, the scariest parts are the nightmares she causes. The thought of being chased by a living doll in your dreams is truly terrifying. Also, the mystery around her origin, that she was made by a witch and has dark magic in her, makes it all the more spine - chilling.
Probably the idea that the doll might be possessed. Just thinking about an inanimate object having some sort of evil entity inside it is really creepy.
The scariest part is probably the idea that an inanimate object like a doll can seem to have a life of its own. Just thinking about it moving around on its own is terrifying.
The unexplained scratches and noises that occurred around the doll are really scary. It gives the impression that there is some unseen and malevolent force at work. Also, the fact that people who interacted with the doll reported feeling a sense of extreme dread and unease. It's like the doll had a power to make people feel uncomfortable in their own homes.
For Robert the doll, the fact that it seemed to have a mind of its own and would move around on its own is really scary. And the reports of people hearing giggles when no one else was around, especially when it was associated with a child's toy, is very unsettling. It makes you wonder what kind of 'entity' could be inside the doll.
The sudden movement of the doll can be the scariest part. Like when it moves its eyes or changes its position without any visible force.
I'm not sure exactly which 'lucy doll scary story' you mean. There could be many horror stories involving a doll named Lucy. Maybe it's about a haunted Lucy doll that moves on its own at night, with its glassy eyes following people around the room.
The scariest part is when the doll moves on its own. Just seeing it shift positions without any visible force is really creepy.
The scariest part is often when the doll moves on its own. For example, if it's seen in a different position from where it was left, it gives a sense of something unnatural and spooky.
The scariest parts are often when Sarah is alone and helpless. Like when she's trapped in a spooky place with no way out. For instance, if she's locked in a haunted attic and she hears strange noises all around her, feeling completely alone and vulnerable makes it very scary.