[Spoilers] Death and reincarnation
One major thing we find out from ShB is that we, the WoL, were likely originally an Ascian that Emet-Selch knew before our soul was shattered into 14 pieces. Furthermore, with each rejoining our soul becomes closer to its original form. Given that the Ascians are thousands of years old while we ourselves are not immortal, this means that the pieces of our soul have been going through a cycle of death and rebirth ever since the Sundering.
It was confirmed in the optional dialogue with Emet that this is true for other Ascians as well - when they elevate lesser Ascians to office, for example Nabriales, they prefer to do it with a fragment of their original soul, although it's possible to achieve with an unrelated individual.
So now we know that there are a bunch of shattered, former Ascians whose soul fragments remain intact even after death (unless destroyed via the white auracite method). What about someone who wasn't one of the original Ascians, that is most of humanity? Do we know one way or another whether their soul survives death? If yes, then we get into some weird existential situations like, what exactly constitutes a unique person and does anyone really die? So right now I'm leaning toward no and that the Ascians are special in this.
I'm curious where they're going to go with this and whether there's any previous lore on the difference between aether and souls, what exactly happens after someone dies, and how new souls are created. Even our method for killing Ascians is starting to seem mysterious.