This article is a Stub.
Residents of a plural system may disappear or die, or may be killed, but we have no evidence that such "death" is permanent. It is certainly painful, and system members and external folk may mourn their passing like any other person.
Many plural systems report that the resident returned after some length of hiatus.
As reported by folk in DID groups, many residents who are reported as dead will undergo a metamorphosis while gone, and return after some time, but also are clearly the same person underneath.
None of this makes their passing or absence less painful for everyone involved, and because they can be missing for years it is small comfort that they will return.
This is unfinished… there's more to say.