Time for more Black Witch! There’s some stuff about the strange incantation in the full post.
Okay, so what about this incantation? It refers to Abe no Seimei and Ashiya Douman, two great masters of onmyoudou, the traditional Japanese mystical art of divination and exorcism. And the incantation itself? Well, looks like the writer was playing a joke. The chant sounds really arcane (and gets called “ominous” in the novels), but it’s just an extract from a work called the Izanagi-ryuu Saimon talking about the ritualistic preparation of a construction site (jichinsai). Yep, Douman’s laying done some ropes, and Seimei’s doing some digging (with a silver hoe).
Oh, and in the original novels, Asakura Ryoutarou was from a yakuza family, but his dad had switched to selling toys. (And, FWIW, it was Barbie dolls, not Kewpie dolls that Gyubid was drooling over.)