TIL Hyperborean comes from Greek mythology and were people who lived in the far northern parts of the known world. It became known to signify remote and exotic locations.
I've only ever heard it used in pulpy adventure stories/comics like Howard's Conan world (some of which do admittedly have some if that implicit racism common to fiction from that time). Has it become more explicitly neo-Nazi?
It’s common enough that tik tok banned the hyperborea hashtag and you can find a couple 4chan threads about it at any time.
I think actually believing in it is pretty fringe even among neo nazis though. It usually involves magic and aliens. It sometimes ties into flat earth and similar nonsense.