In New York, snow was falling heavily, as it was that time of year again- winter. The children ran out of apartments, away from the "dreaded" clutches of over-protective mothers pestering them to put more clothes on, to play and escape the homework that would surely have to be turned in tomorrow if not for a most wonderful snow day.

However, the most excitement was on the north side of Long Island Sound, where a certain white-haired spirit was currently causing quite a commotion.

"WHAT THE- !" Jack Frost banged his staff against an invisible barrier that was preventing him from spreading snow. He could get through just fine, but his staff was held back, similar to how a screen prevented twigs from traveling with the flow of water.

Suddenly, the force lessened, and he went tumbling to the grass-covered earth in a tangle of limbs and staff. Groaning, the spirit got up and rubbed his head. Just because he was immortal didn't mean he couldn't be injured. Positive that everything was intact, he shot up and perched on one of the many trees located in the area.

"Whoa..." The word rolled off his tongue, for it was definitely "Whoa". Kids everywhere were joking around, having fun, sure, but what amazed him the most were all the weapons- but weren't they child hazards?

He shook off the thought. No one seemed to be actually hurt or injured, and his job was to spread winter and fun. These kids already had fun, so winter it was. With a wave of his staff, he called on the wind and flew up, whooping as snowflakes burst from the tip and covered the area in a thin blanket of white- just enough to have a decent snowball fight in. He didn't need a child to trip and accidentally impale themselves on a blade or other deadly items. Guardian of fun he may be, but guarding kids in the first place was, and always would be the most important thing.

His job was done in a flash, and he zoomed off towards the next state so quickly, he never noticed that a certain red-haired girl was watching his every movement, mouth slightly agape.

Boreas reclined on his throne- not that it was very comfortable in the first place. Dimly in the back of his mind, he could hear the voice of Jack Frost, currently where Jokul Frosti, the Viking myth, was residing.

Of course, mythologies, as the mortals deemed them, tried their best to avoid each other, but the original Jack Frost had long ago faded, as mortals no longer feared death from Old Man Winter with all their heaters and temperature control. This spirit, Jack Frost, only received his abilities (which were still limited), none of the old nasty attitude. And thank Zeus for that, too. Boreas didn't need him intruding on his realm, not while Hera was stirring up a new scheme.

Besides, Jack Frost had been situated in America before the Greek Gods came, and wasn't exactly a mythology- so they left each other alone, win-win situation. That is, the rest of the gods did.

Boreas always helped out Jack a bit, him being the North Winter Wind, he permitted Jack to ride the winds and going as far as to allow him a bit of influence over them. It was worth it, accompanying Jack gave him- at least part of his consciousness- a break from the heavy work of being a god, mostly because the situations that the young Winter Spirit got into were so humoring. Pure joy practically radiated from the spirit- though it also contained a hint of sadness and regret. He didn't pay much mind to it.

Although, the god mused, Jack certainly behaves better than Khione does. His daughter had become rather cut off from him recently, and spent much time brooding in her bedroom or heading off to who-knows-where. Speaking of which, he nearly forgot to check up on her- for her own well-being and to prevent her from having a run-on with Jack.

Shit.

Headcanon 1: The main source/channeling device of Jack's power is his staff, and since it bring snow, it is pushed out by camp borders. But hey, isn't Jack supposed to be held out too? He's the Spirit of Winter! I am well aware of that. But the camp borders keep out monsters, mortals, and bad weather. Jack himself is none of these things, so he gets through.

Headcanon 2: "Wind" in the movie ("Wind! Take me home!" -Jack) is actually one of the North Winds. Jack doesn't know this of course. Also, the gods spread out their consciousness, so Boreas decided to have a small part of himself follow Jack in the form of the one wind that he has slight power for shits and giggles. Why the hell not?

Headcanon 3: Jack Frost as we know him has only been around for 300 years, since the colonial times. The original existed up north as part of Viking mythology as Jokul Frosti. He eventually faded, and since this could throw the universe off-balance (You need a deity of each season for each realm), his power was put into the next Winter Spirit- his name was forgotten, but he went by "Old Man Winter" (He wasn't a spirit- just a human with forcefully slower aging, courtesy of MiM). After his death, another took his place- this one had a few believers that called him "Father Frost", since they didn't call him by his first name out of respect. After that came one called "Jack Frost", who couldn't contain the powers of Jokul Frosti very well and died not long after accepting the title. Of course, these accidents led to the deaths of some humans and a few minor spirits.

So, when Jack as we know him took on the job, his name was already stained. Not to mention all the pranks he pulled and the occasional loss of control, the other spirits didn't like him very much. Understatement, but that will be examined in more detail later.

But due to the power(s) being handed off to so many holders, the "Vikingness" faded away through the years and became more inclined towards the Spirit Realm rather than the Viking Realm.

That was a long explanation. Just wanted to share that with you. My personal thoughts that led to this crossover.