Well, as for the styles that they’d practice regularly, that will heavily depend on what their members knew or were trained in before they wandered off from society at large. So, what styles they’d have and what they’d know, that will be up to you to figure out. But, I can point you in the general direction.
If members of the society had a connection to the military (I’m assuming U.S. Military, if you want another country of origin then you have to look up their standard style) which is going to be some variant of C.Q.B (close quarters battle), this style can range from the Marine variety of M.A.P. to the styles practiced by the C.I.A., special forces, and other government agents. It’s cousin is C.Q.C. (Close Quarters Combat) which is the non-lethal/subdual based hand to hand style practiced by the Police and the FBI. Both styles are designed to be very easy to learn and to pick up in a matter of months, if not weeks. While the style is not designed to produce warriors, it does produce very effective combatants.
The civilian variants of Krav Maga and Muay Thai are both brutal and acceptable alternatives if the characters lack military roots.
You’ll have to modify the style and their variation of combat based on their powers, which will mean coupling it with your animal of choice. I suggest looking taking a look at various pack animals such as wolves and lions to get an idea of how these characters might naturally work together as a unit, this will lend the alien/predatory sense to them that you’re going to need. Otherwise, they’ll just come across as human and there will be some question to the point of the powers relating to animals at all. Any general nature documentary from Animal Planet, National Geographic, or the Discovery Channel (or corresponding channels in your country) will work as a jump off point for your research.
If you’re wondering why I suggest pack animals, the reason is this: they live in a community that is isolated from the outside world and they are highly militarized. Militarized communities breed a certain perspective on how they view the outside world and how they raise the members of their society. The kids will be taught to work together from a young age, their combat and survival training will likely be Pack oriented, with a firm untrustworthy gaze (if not open hostility) directed at the outside world. Communities that just want to be left alone don’t militarize, even if they do maintain a militia force. The society you’re suggesting is one with a very complete martial focus and that doesn’t inspire warm fluffy bunny feelings for strangers. For these guys anything that is not them is Other and because the indoctrination starts when they are infants it will be almost impossible to break and I mean that, a quick jaunt into the outside world or even an extended stay isn’t likely to shake their loyalty to their community and is likely to only really inspire a general disgust.
Every military force needs an enemy, even if that enemy is just out of reach. Training soldiers for no reason other than to train soldiers, in a culture that is full of soldiers, who have been raised to be soldiers from birth need to fight. They have to, if they don’t have that outlet, they will turn on the community itself and do battle within it. They are going to need to focus that aggression somewhere and on someone, because they have qualities that differentiate them from humans and some elements of their society may even have embraced the concept that they are no longer human, it makes human society at large an easy target to transform into the necessary evil Other. Eventually, they will become an expansionist entity.
Because the society will have limited members and has a military focus, they will trend towards gender equal out of necessity.
They will also need to be focused on the Good of the Whole as opposed to Individual Gain to keep them in the society and from the society having to promise them (like land) to get them to stay. Even when faced with a hostile outside world, there will be those who want to leave unless measures are taken to coerce them into staying. This can be done by starting young and focusing them on the collective’s needs instead of their own.
Training for these characters will involve a focus on unit cohesion, team building, and creating a sense of brotherhood within the members of the community. It should also engender (if they are actually skilled combatants that don’t rely on berserking) a sense of discipline. This is why I suggested the military and military training as the basis for your study. Because the society is small, retaining the loyalty of their members will be paramount to their survival. Their training from early childhood on will revolve around building that sense of dedication. The children will probably be taken from their parents early, perhaps as young as four, put into the care of an older mentor figure, and mixed into a unit of their fellows. The collective itself will become their parent figure instead of any one individual caretaker.
The training will begin at five and will remain light. Though they’ll learn techniques, attention will be placed primarily on developing the necessary skill sets that they’ll need to serve the community later in life. This will mostly take place in the form of “games” like Hide and Seek (hunt and stalk your prey), Tag (one player acts as a rabbit while the others hunt them down) and so on. When they get a little older (say nine or ten) they may even be allowed out on “field trips” to practice their skills as a test (though in a controlled environment under the close eye of the adults).
If their training goes as planned, then they’ll be accomplished fighters (though not practical, experienced combatants) by the time they are fifteen. They’ll be ready to release into the regular force by the time they are eighteen. (This will have more to do with their emotional and psychological maturity as opposed to their skill level.)
The kids won’t openly spar with each other (in an uncontrolled, non-padded environment) until they are at the end of their training.
Remember, the goal of the training is going to be to develop unity as opposed to individualism. Rivalries will be tolerated until they affect the training and the unit, then they will be mercilessly quashed by the instructor in charge. The kids will always be under fairly close scrutiny, even when they don’t realize that they are, and rivalries will be something that their instructors and handlers will be specifically on the lookout for either to use or suppress. The two rivals, regardless of their skill level, may be allowed to continue their rivalry by their instructors to show the other students the faults of individualism and the virtues of cohesion.
By the time their training is complete, they will be firmly entrenched in the tenants of their society and the concepts of Not So Different will matter very little to them. It will also be fairly difficult to get one alone and away from their fellows without extreme duress. If any more than one is captured (even if they are or were previously rivals) forget about them turning against each other or their culture. Loyalty to their society will win out over any personal desires.
The Psi Corps from Babylon 5
The Jem’Hadar from DS9
The Space Marines (and other subsequent groups) from Warhammer 40k
Survivalist Groups/Cults (With a focus on the sociological and psychological aspects if you can stomach researching them.)
The Marines (with subsequent focus on training and instilling the concept of the enemy Other into the soldiers)
The Spartans (Their training focused on individualism and is outdated in concept when set against any generation of a trained, standing military force. When the Spartans existed there wasn’t really any such thing as trained military combatants. Times have changed, in today’s world, the results of that training would be subpar.)
Stay away from Special Forces, Special Forces are elite but also limited. They do not an Army or Militarized Society make. Go with the lower tiers of military first before looking at these guys and their training methods. Remember, Special Forces training builds off what the soldier learned in basic and the field, while their training can be extreme, it can’t be done with fresh clay. It’s the finishing glaze to a piece of pottery that’s already been through the kiln. Don’t mistake one for the other. (If you must have them, then for psychology’s sake, these will be characters taken in for extra training in their mid-twenties. If you’re writing a YA novel, they are outside your reach, though they will work for antagonists.)
Stay away from any material that proposes starting training with an uncontrolled bout. Anyone trying to turn out a genuine military force isn’t going to force two people into an arena and say fight unless they are a sadist and don’t care about the development of the fighters. The students are only going to hurt themselves and they won’t actually learn anything from the experience (other than bad habits that will be difficult to break later). Many students train for years before they are allowed to fight with no pads and by then they know they’re doing (usually they’ll have progressed to the point of being ready to be teachers themselves).
I stuck this in at the end because while it’s important, it’s also sensitive. We do have an article on child soldiers, but this is different. This is covering training in violence and experiencing violence at a young age. There’s a difference in kids and adults who began training young versus those who begin training when they’re older. The difference isn’t just that they’re better, it produces some interesting psychological and emotional differences that will impact the characters you’re working with.
The Individual is the Violence
For a kid who has been raised in combat, the combat (beyond the violence) becomes an intrinsic part of who they are. This means, ultimately, that fighting will be their natural state and where they feel the most comfortable. Their combat style and training won’t be an aspect tacked on to a ready made individual (like you get with adults), it will be the individual.
It will come to the point that while the individual is able to contemplate and understand the cause and effects of their violent actions outside of the fighting, it’s a disconnect that won’t occur to them when they are in the moment. It works like this: though the character may choose their techniques based on who they are fighting, they may perform those techniques with the same speed and efficiency that they were taught regardless of who they are fighting because the style itself has become a molded extension of themselves.
It’s not a question of right or wrong. It is part of them and will remain part of them long into adulthood. If you’re going to write kids who fight, you’re going to have to start viewing violence (even if you don’t believe or don’t like it) as a normative state.
Lack of Empathy is Key
They don’t empathize with others in the same way, they’ll connect with their group or pack just fine. Strangers, however, are a different story. They will be innately suspicious and wary of strangers. They may understand (but not really) why other people are put off by violence or the injuries they inflict. (Why are you crying? It’s just a gut wound. Get back up.)
And the reason for the lack of empathy?
Violence is Normal
It’s always been this way. Are you telling them that their whole life is wrong? How would you react if someone told you that everything you believed in and everyone you trusted and loved was wrong and evil? (Starke Note: How would you react if someone told you: No, puppies are for eating.)
There’s probably some other stuff in there, but that’s the general gist. To everything, there is a trade off. The younger a kid is and the more skilled they are, the more their personality must be molded around that core skill. To the uninitiated outside observer this blase approach to violence may come off as a wee bit psychopathic, but it’s important to remember that these kids aren’t psychopaths. They come from a society that has a very different standard of normal. Much like the average middle class San Franciscan’s instinctive gut reaction to a picture of a North Dakotan seven year old girl in a princess dress wielding an AK47.
(One important trait that I forgot to add: The Confidence Is Not False. They are that damn good and they know it. Whatever crippling insecurities the characters may have in terms of social interaction or in other aspects of their life, when they’re good at something, they know it and they will look down on others for not knowing and being bad at what is normal to them. See: Altair from the first Assassin’s Creed and his general lack of human empathy. The assassins in the first game and their gleeful poking of Altair while at the same time helping him is a good example of the ways you can play the “family” loyalty. Desmond’s personality, sadly, is not spot on.)