One may see it as an example of shinbutsu-shugo since ritual for repose of souls, based on esoteric Buddhism, was carried out in addition to the custom of vindictive spirit festival based on traditional Jingi belief.
これが神祇信仰に従来からあった怨霊祭り上げの風習に加えて、密教の側からの鎮魂も行われた点に神仏習合の類型を見ることが出来る。