Her hair is originally pitch black & doesn't shine when light touches it, representing the dark void, it can manifest any horror.
However due to a predicted demise in the future, she attatched that part of herself to another person, so she wouldn't be destroyed completely, so for now its white. Though she looks like a frail child, simply gazing at her feels like confronting your worst nightmares due to her being in tune with the unknown.
She's an OC from a childhood story.