Shikigami

Shikigami (式神 shikigami) is a multi-purpose type of magic used by the Onmyouji.

Description
The arts of shikigami involves using one own's magical power to manipulate the shikigami, invisible spirits in the environment, and make them abide by the Onmyouji's will. Carefully crafted talismans are used to enable temporary materialization of the spirits. Shikigami can be used for offense, defense, scouting, reinforcing, manipulation and even giving life to objects, though the main purpose of shikigami is demon exorcism. What can be achieved through the use of shikikami depends on the skills of the Onmyouji. If the evoker is well introduced and has lots of experience, his Shiki can possess animals and even people and manipulate them. But if the evoker is careless, his shikigami may get out of control in time, gaining its own will and consciousness. In this case the shikigami will raid its own master and kill him in revenge.

Trivia

 * Even though it was never shown on screen, Misuzu once summoned a ferret Shikigami to keep track of Yuka and the latter seemed to like it very much.
 * Shuu Amami, while investigating the identity of the Doppelganger, also summon familiar spirits to his aid. Although these are called Familiars, as they are created by Western sorcery, they serve essentially the same function as Shikigami.
 * In 3days, after regaining the memories of his past life, Ryo Takanashi summoned sparrow Shikigamis to search out for Miyu Hiiragi's whereabouts. Due to the low magical potential of his current body, he could only summon four of them.
 * The four Black Knights Acedia, Invidia, Ira, and Gula are actually, in strict sense, Misao's Shikigami. She use the Technique of Returning Soul to bind their souls into Larvae, giving them their names to make them forget their former self and eliminate their sense of self. This also helps keep their souls in check, since if they remember their former selves, nature will take course and the Larva body will dissolve. There was risk that the Larvae would invade their mind and make them go berserk, which was the case of Gula. Invidia, after remembering herself, was under the danger of being dissolved. Fearing that her sense of self would hinder Avaritia, Misao made her explode to kill Kakeru Satsuki and the Fragments.