Occasionally, a soul can be so full of rage and hatred that after death, it manifests as a particularly powerful creature. Sometimes this can even happen while the victim is still alive, though only under specific circumstances in areas possessing a high concentration of magic.

Living or dead, the resulting transformation is the same, with the afflicted becoming a Curse Spirit.

Most often reported in Neighpon, Curse Spirits (from their Neighponese name, Tatarigami, meaning "curse spirit" or "curse god") are powerful spirits which bring death and destruction, fire and famine, plague, war, and all forms of calamity. They are some of the most powerful evil spirits that haunt Neighpon, and have supposedly done much to shape the culture and politics over the country’s long history.

Tatarigami wreak havoc upon those who wronged them- usually other nobles. In order to appease their vengeful spirits, shrines honoring them have been built across Neighpon. Through proper appeasement, their curses can be lifted, or at least abated.

The Gion Matsuri in Kyōto, one of the most famous Kirin festivals in Neighpon, is an example of a ceremony initially designed to appease a tatarigami. 1,149 years ago, the Kirin's capital suffered a number of outbreaks which were thought to be caused by Susanoo and Gozu tennō- two powerful gods of disease and destruction( specifically, Susanoo is a god of the sea and storms, while Gozu tennō is a deity of pestilence). In order to appease their wrath, a festival was held in their honor. To keep the city free from disease, the festival was repeated every year. Eventually the connection to Susanoo and Emperor Gozu was lost, but the festival traditions remain to this day.

Someone been watching Princess Monaoke

6314671 https://www.fimfiction.net/group/199698/the-known-world/thread/350490/races-shishigami

6314671 Mononoke

6314677
Dammit I was right the first time around