Evil Spirit, Akuryou (悪霊)
Portrait of a vengeful spirit in Subterranean Animism
A vengeful spirit (怨霊 onryou) is a special type of ghost created under special circumstances. When a person dies, they must wait on the Sanzu River for a shinigami to ferry them across. However, if a youkai steals their body away before they cross the river, that person will become a vengeful spirit. Unlike normal ghosts and phantoms, vengeful spirits are hot to the touch.
An evil spirit (悪霊 akuryou) is another kind of vengeful spirit, briefly referenced across the series.
Mima is described to be an evil spirit in her profile in Mystic Square, making her the only known one thus far. Evil spirits were mentioned by Reimu Hakurei on the first stage of Embodiment of Scarlet Devil and again in Chapter 25 of Curiosities of Lotus Asia, where she describes an evil spirit (presumably Mima) taking over the Hakurei Shrine. It is unknown what exactly makes evil spirits distinct.
Vengeful spirits in Touhou
In Wild and Horned Hermit, Kasen Ibara describes them as criminal spirits, those that committed sins while alive. These vengeful spirits were confined to the Former Hell, but leaked back to the surface due to the acts of Rin Kaenbyou, who learned how to control them. Vengeful spirits are feared by humans and youkai alike throughout Gensokyo.
Recently, the Underground Geyser Center has been plagued by these vengeful spirits.
Not to be confused with normal ghosts and poltergeists, vengeful spirits appear to only take on a non-human form, and Soga no Tojiko is described in Symposium of Post-mysticism as a vengeful spirit who is losing her grudge and becoming a simple thunder-causing ghost. In the prologue to Subterranean Animism, they are referred to as earth spirits (地霊 chirei), but in all the dialogue, as well as the extra story, they are referred to as onryou. Their appearance mostly involves a skull in a form of a spirit.
Mizuchi Miyadeguchi is a vengeful spirit.
Vengeful Spirit's Appearances
Vengeful spirits appeared on stage 4 of Subterranean Animism, supporting Rin Kaenbyou during her midboss appearances as a cat. On stage 5, they independently come in groups and cause an explosion of danmaku towards the player if destroyed. They are again supporting Rin during her battles on the stage. On stage 6, they'll some scrolling down the screen in long queues. Strangely, they are not shown to have a skull. Despite their similarities on their sprites, they are not to be confused with the divine spirits in Ten Desires.
- Foul Detective Satori
First occurrence of vengeful spirits, as seen in Subterranean Animism
- In the data files for Hopeless Masquerade, the spirits were named "dokuro" (髑髏, in kanji form), which means "skull".
- Wikipedia entry for Onryou