(Well, I'm gonna make me a skin-walker, and you can tell me if I've gone too far or not. The whole "adept" thing isn't quite what I had in mind, but I'll try to work with it.)
Name: Kaden "Kai" Greer
(Kai is his Navajo name)
Age: 26
Gender: Male
When he is human, his eyes reflect light like an animals, but conversely, when he is an animal, his eyes appear almost human, and do not reflect light as much.
Race: Human (technically)
Magic: Adept
Skin-walker: A skin-walker is a sort of witch, who uses dark magic, charms, rituals and can transform into animals. It also makes him a bit harder to kill than a normal human. For a normal wound to be fatal, silver or white ash is necessary, but otherwise a shot to the heart or decapitation will suffice.
Transformation: By performing a short ritual while wearing the pelt of an animal, he permanently gains the ability to shift into it, even without the pelt. He currently can transform into a crow, a cat, a dog, and a wolf.
Consciousness shift: Part of the skin-walker legend is that one can absorb themselves into another person, or paralyze them by looking into their eyes. Kaden cannot do this, but he can transfer his consciousness into another animal. He cannot control it, but he can see what it sees and hear what it hears, so long as it stays somewhat nearby.
Equipment:
Ritual bag: A bag of bones and dust that he can use for dark charms.
Bone darts: Darts that inflict a strong sense of fear upon the victim and leaves barely perceptible wounds.
Corpse dust: Bone dust that can poison the victim to varying degrees. Usually not fatal.
Blow gun: A simple wooden pipe for shooting darts.
Skinning knife: Just a knife for when he needs a new pelt. Also kills people fairly well if needed. Has a deer horn hilt.
Hatchet/Tomahawk: Just an axe for when he's in the woods, or needs something bigger than his knife. He can throw it with decent accuracy.
Personality:
He has a very dead-pan personality, often making very dry jokes without laughing himself. He is very laid back and slow to anger, and in a tense situation is usually the last to lose his cool. However, he is sorely lacking in empathy and while he usually can play nice, he doesn't win friends easily either. At best, he has "acquaintances." At worst, he's terribly insensitive at the wrong moment.
History:
When he turned twelve, he learned of his heritage. He was part native, and was from a lineage of skin-walkers. The dark ritual to become one was forced upon him, and his pet cat was killed in front of him, to test to see if he would be able to successfully absorb its essence and transform, and also to begin slowly twisting his emotions from being a normal, happy child to being a practitioner of darker magic. He was taught all about the rituals and dark things that native witches did... and he became quite good at it. However, he had a spark of independent thought. He swore to himself that he would commit one, great sin -- and then never again.
He killed his entire family, using the dark magic they'd taught him. In a way, it back-fired. In removing their darkness from the world, he took it upon himself, twisting himself further. He became more cold on the inside than his family had ever been. However, he ran on autopilot, continuing to work toward something better as he'd promised himself he would. He would use his horrid magic for something good, even if it isn't what he really wants anymore. Then again, he didn't know what he wanted anymore.
However, after some years passed, he found a little direction when he stumbled across certain bar filled with an entire community of people not too different from himself. Other people who had magic, weren't human, and dark pasts. He chose to stick around, hide what he was from the rest of the world, and wait until a path opened itself up for him. Maybe his chance to do good would come.
(OK, that's what I came up with. I can dumb it down to be just "an adept magic user who turns into animals" if that's what you'd prefer. I tried to keep it more in line with the original Navajo skin-walker legends though. Just let me know if anything isn't acceptable and I'll go fix it.)
