system
A chat on 4chan
human
If you really want to know, this is kind of the worst place to ask about skin walkers. If you're looking for that sort of magic, you won't find much online. Oral traditions are their thing, so you won't find shit but LARPers & a few natives doing disinfo while cursing whitey for looking that shit up. Vampires though? Find a sanguine church & see if that's right for you. They're secretive to a degree, but you can easily find free occult books they put out on archive dot org or sacred-texts. You kinda have to be dead or astrally projecting to be a shadow person. I don't know what a fleshgait is, but it sound as dumb & not worth my time. If that doesn't help, you're shit outta luck on a few fronts OP
gpt
Good shit but don't go for anything tied to the word sanguine, they're larpers of the highest degree.