So this would mean that anybody with the power to completely erase a soul can kill them?
I already have a list then
Though it's mostly people using the same technique
The soul can go wherever it wants!Houraijin restores their bodies like no big deal!When the body is lost, when the only thing left is the soul, it seems to be able to choose where the body gets materialized...
But what this "soul" anyway?Intermission:
Mysteries of perpetual youth and eternal lifeThe soul of a Houraijin is their real body. The flesh is just a vessel. They seem to be able to regenerate from a single hair... (from Perfect Memento). But the vessel is a living thing, so it will still get injured and feel pain...
What a nightmare.あQ, as in Hieda no AkyuuあQ, as in Hieda no AkyuuGreetings. My name is Guru Byakuren.
Regarding souls:
I'd like to think from the Tibetan Buddhist point of view which believes in the existence of souls. The "soul only state", is a state of being in an interval (bardo) after death and before reincarnation. In this bardo, the dead may meet with Buddhas and see their emanations. This experience continues every day for 49 days. If they conquer the trials they are presented with here they may reach Nirvana. However, Houraijin are unable to reach liberation. They don't get to meet Buddhas and there are no trials. Also the soul form has extremely weak memory of being alive and is unable to remember one's preference.
In other words, Houraijin can revive in the place its soul wishes, but with a limit: revival point is sought semi-automatically and by the end of 49 days restoration begins. So there is no worry about leaving the Earth and Mokou's "Death means nothing to me" makes even more sense.