I forgot to mention this before, but the original plot idea for a Hayate-is-Dean's-daughter story did not originate from me. That can be entirely laid on the shoulders of edboy4926 who asked for a Supernatural/Nanoha crossover.
Sam and Dean couldn't wait to get this hunt over with so that they could hit the Roadhouse once Sam had his interview. Dean just knew that Sam and Hayate would get along great...they were both total bookworms.
They had finished the hunt in what Dean considered record time, though he had a bad feeling as he was driving them back to Stanford. Like something awful was about to happen and there was nothing he could do to stop it.
That feeling panned out when he had to grab his brother out of a burning apartment building, his girlfriend pinned to the ceiling... just like their mother was when Sam was a baby.
Dean had a sinking feeling that this was just the start of something. Something much, much worse than their family had ever dealt with before. And he was afraid for Hayate.
"What? Yeah, I'll tell her. We'll be sure to make the place a fortress and Jo will take her to and from school. She's in the dining area now... See you in a few days," said Ellen.
Hayate perked up. She could always tell when her father called to ask about her.
"Your dad's coming here in a few days. And he's bringing someone you'll love to meet. Unfortunately he said that there was an incident, so no library without Jo there with you until he gets here, okay?" said Ellen.
"Okay Aunt Ellen," said Hayate.
While her English skills were coming along much better, her accent was still there. So long as they could understand her, Dean didn't care if she kept it. Since it felt weird to call Ellen mom (and she refused to be called Grandma on the grounds that she was not that old), Hayate started calling her Auntie. She called Bobby Grandpa, mostly because he acknowledged he was that old and he practically considered Dean his son.
A few days later Dean came in and immediately went to where Hayate was drawing in her book. Ellen encouraged her to keep up her clothing designs... Hayate was quite the little designer and it made her happy despite the fact that for some reason she had great difficultly walking.
Dean had been upset, especially when he found out that there was nothing physically wrong with her spine to cause slow paralysis.
"Dad!"
"Hey kiddo. How's the designing going?"
"Okay. Jo said she can take me to the fabric shop later once I helped her out with her math homework. It's so easy!"
Dean chuckled. For some reason his kid was a little math genius and Jo took full advantage of Hayate's ability to understand advanced calculus to help her get her homework done faster. In exchange she helped Hayate get new books and things with the money she made beating other hunters at poker.
"Who's the giant?"
Dean snickered at Sam's expression on his face.
"The...giant... is the man I want you to meet. Hayate, this is your Uncle Sammy. Sam, this is Hayate."
"Uncle Sam?" she said.
Sam bent down to Hayate's level. He noticed she had some trouble walking and wondered why.
"Hey there. I'm Sammy."
"Dad said you like to read books a lot."
Sam gave Dean a glare.
"So how long have you had trouble walking?"
"For a long time now. The doctors back in Uminari couldn't find what was wrong," said Hayate.
Dean had mentioned Hayate's mother was Japanese.
Sam then had an idea. To the amusement of Dean, Sam gave Hayate a lift on his shoulders. Hayate squealed with delight from being so high up.
"Demon possession. Are you serious? She hasn't shown any sign of being possessed and she passed all of Bobby's usual tests. Didn't even flinch from salt and holy water," said Dean.
"Think about it Dean. There are some cases where the possession is a slow-going one, only those are near impossible to spot until it's too late. And it would explain why she has been having trouble walking without any medical reason why."
"How can we find out if that's the reason behind Hayate's paralysis without her learning about our job?"
"Teach her the exorcism. You said she was trying to learn English right? Why not teach her Latin too and see if we can get her to say it instead of us?" said Sam.
Dean liked that plan. It was a way to teach Hayate a new language without her finding out about hunting. And it was harmless enough.
Sam slowly introduced Hayate to Latin. Dean had told Ellen the plan to see if Sam was right about the slow possession, and while she wasn't happy she allowed it. In between hunts Sam got to know his niece and he had to admit that Dean was a better dad than John ever was.
"Uncle Sammy? What's this phrase mean?"
Sam looked at the passage in Latin and translated it without thinking.
Hayate proved to have quite the knack for languages, as proven by the fact she had learned basic English in two months. So far she could just barely keep up with Sam, but conjugating the words so that she could form sentences was difficult and it didn't help that Latin was a dead language.
"Ready to try again?"
Hayate nodded. Sam had been waiting for this moment for months. Since they were at Bobby's house (Hayate wanted to see her 'grandfather' and Dean had obliged) it was the perfect time to see if Hayate could recite the exorcism. Dean and Bobby were outside arguing over some car or another.
"Let's see you try this one. Remember, you just have to try and say the words right, not translate it. We'll work on that later," said Sam.
Hayate nodded brightly and started sounding out the exorcism. So far she had gotten most of it right, but Sam had to correct her pronunciation a few times before she got it. Her accent was a bit tricky to work with.
About three-quarters of the way through the exorcism, which wasn't that long, Hayate started to look like she was uncomfortable.
"Uncle Sammy? I feel weird."
"How weird?"
"Like there's something pressing on my legs," said Hayate.
Sam knew that he had been right about the slow-possession. Which meant he needed her to complete the exorcism before it figured out what they were doing.
"You want to continue?"
Hayate nodded. She wanted to get this done right so they could have fun reading more books. Bobby had quite the...interesting... collection. Hayate loved reading about the occult.
They soldiered on, and it took Sam a few moments to realize that something or someone was screaming. Rather loudly at that.
Dean and Bobby definitely heard it too, because they rushed in to find the source.
It was coming from Hayate's room.
"Sam, what the hell?"
He merely handed his brother the same ritual Hayate was trying to pronounce with an 'I-told-you-so' expression on his face...or what Dean flippantly liked to call Bitch face number four.
"She was reading this?"
"I told you something was up with her paralysis," said Sam.
Sam went back downstairs with a very confused Hayate while Bobby said the ritual properly. The book Hayate had brought with her from Japan, which had been bound in chains for some bizarre reason, once again put up an unholy racket as something foul began to try and break free.
The second the last syllable was said, there was a black mass that came streaking out of the book...and the chains suddenly broke without warning.
Anfang.
"Bobby, what the hell is going on?" said Dean. He had his gun aimed at the book, completely confused what was going on.
"How the hell should I know, idjit?!"
Hearing Sam's surprised yelp from downstairs, Dean raced to find out what the hell was happening.
What he found had him even more baffled and confused.
There were four people under what was clearly a ritual circle (though not one he recognized offhand) and one of them had dog ears.
They called themselves the Wolkenritter and claimed to serve Hayate, which made absolutely no sense.
Hayate was out cold in Sam's arms, probably from the sudden shock she had just had. The appearance of the strangers was probably the tipping point.
Dean was most definitely not happy.
"So let me get this straight. You're tellin' me that you lot (Bobby nodded to the newcomers who were dressed in very odd clothing) came from that book Hayate brought with her. A book that up till this point was bound in chains," said Bobby carefully.
The leader of the group (who called herself Signum) nodded. The first thing Bobby had done was test them out and nothing had effected them. Not even silver for the wolf-man.
"We serve the Book and whoever is the current Master," said Signum tonelessly.
"And that master is my daughter, Hayate?" said Dean. He was taking this well, considering, but he was not happy. At all.
"Yes."
"And you have no connection to hell or any other form of demon," said Dean.
"We've never even seen it, nor do we know what a demon would look like," said Signum.
Dean had a headache. So did Bobby.
"Look, why don't we do a wait-and-see approach. I don't know about you guys but today has just been one headache after another since that thing came out of the book," said Sam tiredly.
"What book?" said Signum sharply.
Sam brought out a familiar book.
"We were concerned for Hayate, so we decided to check on some of the things she had with her to see if they were the cause of her illness. I'm pretty sure that this book had something in it that didn't belong, causing her slow decline," said Sam flatly.
It wasn't the full truth, but it was good enough for most.
"You're saying that the Book of Darkness was possessed?" said Signum incredulous.
Looking back on it, Signum realized it would explain a lot. Like why they had difficulty remembering masters once they were sent to a new one. Or why the few times they had looked into a world they had been based on it was destroyed shortly after the Book was complete.
"Is it really called the Book of Darkness?" asked Sam.
"It's what we've always called it," said Shamal, the blond woman.
"Perhaps it was called that after it was possessed by a demon. Either way, that thing is gone now and Bobby said he has something to keep her from being attacked again by anything similar," said Sam.
"We would never allow anything to harm Master Hayate," said Signum sharply.
"Look, we're all tired after dealing with today. How about tomorrow we take two of you on a hunt and see how good you are?" said Dean suddenly.
He was exhausted, frayed, and quite frankly there wasn't enough coffee to deal with this shit without alcohol in it. And Dean wasn't drinking with his daughter in the house.
"The red head can stay with Hayate, since I have the feeling none of you are willing to back down from keeping her safe," said Sam. From the way they acted, it was almost as if they expected to be attacked at any moment. This would keep the peace between both groups until they figured out what they were going to do with this mess.
"Acceptable," said Signum.
Dean and Sam took Signum and Zafira out on a pretty basic hunt. It was one of the best ways they knew to see how people really were.
It took someone of good character to hunt the things they did without any chance of reward in it.
They came back a few days later...and told Bobby that the Wolkenritter were alright, for something they had never encountered before.
To get a 'Winchester seal of approval' as Bobby called it, these Wolkenritter must be good hunters. Though Bobby did not look forward to telling Ellen that she had four new 'guests' in addition to Hayate. At least Vita (the smallest and 'youngest' of the quartet) could share with Hayate herself.
Ellen wasn't happy about the new bunch. Especially Zafira, but that had less to do with the fact he was a man (of sorts) and more to do with the fact he was a canine. Ellen was allergic to dogs, to Jo's disappointment.
Fortunately for the canine, Ellen's allergies weren't set off by his fur. But he still had to stay outside unless it was raining.
Vita was given the dubious honor of being Hayate's guard, while Signum and Shamal were her escorts. Shamal was quickly liked by the hunters at the bar when they found out she was good at first aid...though Ellen made sure that it was regular aid and not anything to do with their magic.
Signum however was the one most often drafted into hunts with Dean and Sam.
Peace was kept between the Wolkenritter and the hunters, at least for the moment. But even more questions would arise from something that would happen three months after the sudden awakening of the book.