awkward potato:
Fantasy kdramas that I can think of right now:
They're not exactly xianxia, but they do have deities and other Korean folklore characters in it. Most of Korean fantasy dramas are in modern period. There are more out there which has themes of mermaids and vampires as well.
I've seen Korean Odyssey and Tale of the 9-tailed.
I think kdrama is mostly focused on ghosts, spirits, afterlife, reapers, reincarnation, etc. And they are mostly modern period dramas.
I would say Korean Odyssey is the only kdrama I've seen that is closest to what I am talking to, as it has deities and wider range of supernatural beings.
While Tale of the 9-tailed is more like Goblin and Hotel del Luna, Black, with afterlife, reapers, ghosts, and supernatural beings.
Maybe xianxia is a purely chinese concept. However this kinda of "god realm" concept does exist in western culture, and also egyptian gods, Ra. Greek and roman gods, Zeus, and probably the best known are the norse gods Thor and Odin, and Asgard as the god realm. So in western pop culture xianxia exists in Marvel movies :)