A/N: For my story Horizon. Here is Sib's back story. This is not required of you to read unless you want to learn about her before reading and are curious of the demon mentioned in chapter one. I do recommend going over it but most of the information here will be touched at least slightly in the actual story.
Sib has been hunted by a white-eyed demon her whole life.
When she was a baby her family died and she was forced to go into a foster home, it was not until later that she found out what did it. The Michaelson's, family of three, raised her for 4 years, giving her the name Cassidy and making her life amazing after what had happened. She never knew her real name. She had frequent nightmares, to the point she had to be put on medicine. The demon finally showed itself to her on the night of her fifth birthday.
That night she snuck into her parent's room and slept with them and the next morning there was screaming downstairs and the bed was empty. Cassidy shot out of bed and came down, following the screams to the backyard. There covering the grass was the carcasses of neighborhood cats. They blamed her and put her into counseling, but even at Cassidy's young age, she had the idea that her step mom knew better.
The older she got, the worse the nightmares were and the more frequently she saw the demon. She was on more medicine and constant counseling, and when she turned ten it made another move. She woke up with her real mother beside her, but when she reached out it turned into the demon. She went to go get her step parents and saw it hovering over her step mom but Cassidy was able to wake her up before it could do anything.
That night she stayed in bed with them, watching over her family until she finally passed out. The next morning she woke up to them dead beside her, throats sliced and hearts ripped out. The girl was nearly blamed for their death and she was on the news. Everyone thought she was bad luck.
From then she lived in the local orphanage, studying and trying to figure out a way to stop it. She developed some sort of power but before she had a chance to execute any of her plans the demon killed everyone within the Orphanage on her 15th birthday. Cassidy stole whatever money she could find off the bodies and the donations box, leaving town before the cops arrived.
From her hometown of Hartford, Connecticut, Cassidy traveled towards Salem, Massachusetts. On her way she found a man named Thomas. He took her in off the street and the first night when she had a nightmare, he had her explain her story. That's when she found out he was a hunter. He had heard rumors about her and the thing following her, even about her gifts. In fact, the whole community of hunters knew about her. Thomas was taxed with helping her but once she told everything he realized how bad things were.
So Cassidy stayed with him and learned his trade. They traveled together. The thing wasn't going to die easily and he believed she was born to hunt so he taught her all he knew. They figured out a lot about the demon together, even went on hunts together. The demon only seemed to kill every five years. There was some reason it was killing the people around her and never Cassidy herself, they just couldn't find out why. The white-eyed demon was some sort of unknown and unheard of species, a rare and unusual cross between an Alp, an Incubus and a Banshee.
Those years of her life seemed to be the best. Thomas was a father to her and some days she wouldn't even have nightmares. Frequently the two would make visits to Bobby Singer, another hunter. That was when she first met the Winchester boys. When they stayed with Bobby the three of them would go out into the woods and play around, make campfires and talk about the hunts they'd went on with their elders.
Nobody liked the name Cassidy, nobody thought it fit her. Her and the boys could never decide on a good one until Sam came up with the idea of making her name an acronym. They threw words that described her into a little hat and on her 16th birthday drew a few out. The words were intellectual, sassy, sensual (Dean's contribution) and beautiful. After the realization that Biss was not a good name and adding an L to make Bliss made her sound like a porn star- the three settled on Sib. Dean demanded the S still stood for sensual, not sassy.
As they got older they were able to go hunting together and did so avidly, the rest of their time was spent hanging out and researching the thing chasing Sib. Despite all of this, Sam left at eighteen. Dean and Sib stayed together and continued their friendship, relying on each other for support because of Sam's absence. Sam kept in contact, emailing her frequently any information he found out about the white-eyed demon. That little bit of communication still didn't fill the hole he'd left for Dean and Sib to fill on their own.
The two of them forged a bond as the years passed, dedicating more and more time to the one another until they were each other's only social life. Dean claimed it was too hard to get attached to someone who wasn't in on it, and Sib seemed to be his perfect match. The two dated on and off for years.
As her twentieth birthday approached, Sib got more and more distant and nervous. She begged Dean to leave her but he wouldn't budge. He felt like it was his job to protect her. The night of her birthday the two of them sat in wait. Thomas never came home, the demon never showed itself. John took Sib in with not even a bat of an eyelash. Sib wasn't the same, she thought she was putting them in danger by being there. John became this strange uncle to her. The nights she couldn't sleep he'd tell her stories. Dean saw hope despite everything and they continued their relationship rockily until his own dad went missing. The mixture of things happening caused them to sort of "split" on the way to Stanford with no hard feelings. Dean would never admit to missing Sib even if he did (which in fact, he did miss her and he still does).
The years that followed were filled with hunting and a slight renewal of faith now that the trio was back together. Finally on her 25th birthday the Winchesters were able to successfully kill Sib's killer.
Hopefully, it stays dead..
