Back at home, when he has time to examine it more closely, it quickly becomes obvious why this ritual never turned up in all his early research. It's not a typical soul summoning ritual. It's not a cultivation ritual at all; as Nie Huaisang puzzles through it, the closest category he can put it in is folk magic...not only that, but sex magic.

A very specific part of Jin Ling's Yunmeng Jiang heritage makes itself known when he comes of age. His friends help him out.