I agree, there is certainly (specifically) Han Chinese literature/legends that associate(or more blatantly, assign) 蛊 to ethnic minorities in China. The outfits are definitely inspired by traditional ethnic minority attire, but I’m not confident which group since the designs aren’t necessarily one-to-one. At the same time, 蛊 appears in many stories nowadays without reference to real ethnic groups, so I’m not sure if the author did this one purpose or if it was a coincidence. That being said, the story can
definitely be problematic, but I’m not sure if it’s fair to conclude that the story is stereotyping as of yet. Of course, I will eat my words if the author does turn out to be taking this story in that direction.
Gu God is wearing attire that looks like Hmong traditional attire and accessories, and calling him the “Gu” God (Gu poison, related to the stereotype of Hmong people using the Gu poison and witchcraft) is lowkey problematic..and bad representation but idk I might be wrong I’m just pointing it out