EzekielRaiden
Follower of the Way
I dunno if it would even necessarily need to be "soulless." Perhaps they have souls, but their souls are the metaphysical equivalent of volatile memory or a wax slate. Scrape the slate, and whatever was written on it is gone. Doesn't matter if you bring the soul back to life directly or indirectly--the person they were just doesn't exist anymore.Yes, I was using sentient in the classic SF way - 'self-aware' - regardless of the pedantic correctness of it.
All of which has nothing to do with my original point. It would be nice to have a species that is both soulless and self-aware, just as equal as any 'ensoulled' creature. One shot at existence, no resurrection, no reincarnation, what you see is what you get, and not be considered "gross".
Perhaps call them the "palim," after the Greco-Roman palimpsest. The you that is, is the only you that can ever be. Death, even for a moment, wipes away all you were. This works best with a synthetic race that can be understood in a "death means factory settings reset" kind of way, so that if resurrected they aren't literal infants incapable of speech or locomotion (mostly because that just has too many problematic/squicky connotations.)