Pathworking is a magical imagery technique, used in current western magic, in which subject is lead through inner pathways of consciousness to experience archetypical visions
Here’s a definition I found however, from what I have found it was normally or “originally” used in kabbalah workings and tarot workings. I could be wrong, but that’s what I found that a few definitions seem to gear it towards but over time it’s been added and expanded on.
They can, many people have went into creating these worlds in the astral/mental even the author themselves can unconsciously create them as they write them if given enough emotions put into it to a point even they feel it’s real.
Ah. H. P. Lovecraft was a famous horror novelist a longish time ago. He made classics such as The Call of Cthulhu and The Shadow Over Innsmouth. Deities like Nyarlathotep and Cthulhu were supposedly made in a spur of madness, nightmares and a fascination with all that cannot be comprehended.
He made them up, but they are common staples of the occult as thoughtforms or paths of magick.
There is a lot of debate on that in the occult community. I, personally, agree that they are indeed fictional, but many feel otherwise, and like to claim they are real, and visited ol’ HP in his dreams, since dreams were the inspiration for a lot of his fiction (but certainly not all of it).
Ultimately, though, it doesn’t matter. Magicians work with fictional concepts all the time, with powerful results.