The Pavilion Master can’t leave the city? Or is it that she won’t leave the city? Just going to make a wild and out there guess that the city could be a massive mystic garden, which is why the pavilion head is so interested in destroying all other gardens. The gardens the paranormal patrol is taught benefits the city (aka pavilion head garden) and regular gardens challenge the master’s authority or something. I recall that the city used to be much smaller, which would be in line with gardens expanding the stronger the cultivator becomes. Hopefully this isn’t just completely debunked in the next few chapters, or by previous chapters I’ve just forgotten.