To read Iizuna Saburō, one must overlay three strata: the syncretic honzon-image of "Izuna Gongen," the heterodox art of the "Izuna method," and the devotion of the Warring-States commanders.

The antiquity of this faith is backed by the texts. The Asabashō^[3] of the first year of Kenji (1275) carries the name of Mt. Iizuna and its founding ascetic; the Togakushi-san Kenkō-ji Ruki (1458)^[1] records "Izuna Saburō" and "the third tengu of Japan"; the Iizuna-san Meguri Saimon (1546)^[4] gives the origin as the Chira Tengu come from Tenjiku; and the Iizuna-san Ryaku Engi^[5] transmits the honji-butsu and the lineage of the Sennichi-dayū. From Kamakura to Edo, it is a faith handed down in layers.

The iconography of the honzon is profoundly distinctive. A crow-tengu holding a sword and a rope rides upon a white fox, with a snake often coiling about the fox. Its honji-butsu is expounded now as Fudō Myōō, now as Dakini-ten, varying by source. It is precisely this composite character—"tengu, fox, Fudō and Dakini" joined in a single body—that is the reason Izuna Gongen, surpassing a mere mountain tengu, became a point of concentration of esoteric ritual power. At Takaosan Yakuō-in, the Iizuna Shrine of Shinshū, Jinya-ji on Mt. Kano in Chiba and elsewhere, the faith is especially deep in Kantō and to the north.

The "Izuna method" is the practical face of this ritual power. This sorcery, which employs tengu and kuda-gitsune to heal illness and, by possession, to deliver oracles, was counted a heterodox art alongside the Atago Shōgun-hō and the Dakini-ten-hō, and those who wielded it were called Izuna-tsukai. The folk belief that one kept and employed kuda-gitsune within a bamboo tube made the very name "Izuna" a byword for witchcraft.

And it was the devotion of the warrior houses that raised Iizuna Saburō to a war-god. It is famous that the crest of Uesugi Kenshin's helmet was an image of Izuna Gongen; there is also the case of Takeda Katsuyori granting the name Nishina to the adopted son of the Sennichi-dayū, and commanders such as Hosokawa Masamoto who practiced the Izuna method itself. As a god who governs victory in war, Iizuna Saburō is, even among the forty-eight tengu of the Tengu-kyō^[6], the seat most bound to this-worldly benefit. Chigiri Kōsai^[7] of tengu scholarship placed this many-sided Iizuna Saburō within the system of the great tengu of the many mountains.