Many as being lives in the world, sometimes beings choose to force their way in.
One such being is Kelnia; once a woman named Kelsy Olnela, she suffered from a simple form of mental instability that made her see things that wasn't there. However very few realized that such madness ended up becoming a doorway into her body and soul, the beasts and madness from the other-realms taking residence inside of her, changing her bit by bit. She broke one day, and ended up fusing with them, creating a new brand of monster; an Undying.
An undying is a human or humanoid creature that fuses or is controlled by someone beyond mortal comprehension, such as the old ones or other such creatures. They become near impossible to kill, The stronger ones even able to be completely destroyed before just popping up in some confusing location, such as on a toilet, or in someone's broom closet.
Kelnia is one such Undying, eternally mad, excitable, and very simple minded untill angered.
She is typically chained down in very painful looking spikes and chains, but a good amount of the time is free to cause a bit of cause. For some reason she flat out refuses to be near anything smelling of coffee, even violently so if forced near it.