The exorcism practices in medieval and modern Onmyōdō

Introduction
Onmyōdō is a branch of Japanese esoteric practices, which is a mixture of natural science and occultism.
Onmyōdō can be considered as a special esoteric vision of reality typical for Japanese aristocracy during the Heian (794-1185) period.
After transition to the period of Shogunate Kamakura (1185-1333), Onmyōdō practices gradually lost their power and became forbidden for centuries before repeal of the law in 2006.

The branches of Onmyōdō
Onmyōdō
Fortune-telling Protective Exorcism
practices practices practices

Research Questions
How the exorcism practices of Onmyōdō are held?
What are the main reasons for a soul to become a vengeful ghost (Yūrei) in the terms of Onmyōdō’s believes?
Which types of Yūrei exist in the terms of Onmyōdō?
How a soul can be relieved during the exorcism practices?

The procedure for conducting exorcism practices
Onmyōji – professional practitioners of onmyōdō
Paper dolls. Through them Onmyōji summon Shikigami,
spirits conjured to exercise risky orders for their masters,
such as protection from Yūrei.

Yūrei

The reasons of becoming an Yūrei
Yūrei is a vengeful ghost in Japanese folklore.
A soul can become an Yūrei:
If a person committed suicide.
If a person was tortured to death or suddenly died in a painful manner.
If a person was betrayed or had regrets before death.
If a person did not manage to finish an important task. Most often the task is a revenge.
All Yūrei are driven by powerful emotions such as a desire for revenge, love, jealousy, hatred or sorrow

Types of Yūrei

Onryō
Vengeful ghosts who come back from purgatory for a wrong done (murder, torture, betrayal and etc.) to them during their lifetime.

Ubume
A soul of a mother died during childbirth or died leaving young children without care.
Ubume is not a vengeful ghost, it is just a suffering ghost who is chained to the world of living because of its love to the child.

Goryō
Vengeful ghosts who are very close to onryō, but their souls belong to the aristocratic class.

Conclusion
Exorcism ceremonies of Onmyōdō might have a diversity but they always include an Onmyōji and a summoned Shikigami.
For a soul to be relieved an Yūrei must be reassured by an Onmyōji. Otherwise their suffering may last for eternity.
All Yūrei can be divided into some types depending on the way of death, their age, gender, the emotions they experienced before their death and etc.

Sources
Reider, Noriko T. (2010). Japanese Demon Lore: Oni from Ancient Times to the Present.
Meyer, Matthew (2014). "Rokujō no Miyasundokoro".
Hayashi, Makoto; Hayek, Matthias (2013). "Editors' Introduction: Onmyodo in Japanese History".