[Unukalhai & the WOD] Why is this not mentioned by anyone?

[Nialle]

[Spoilers for the 3.5 Triad Quest]

We know that in order to cross the Void to other shards/worlds, a soul needs to die and then find a body to possess in the destination realm -- we've had it explained about Ascians (as well as voidkin like Succubi and Mindflayers) -- that every one of them we see is actually an incorporeal being using the hijacked body (living or dead) of some poor Eorzean, like Lahabrea did to Thancred. I also assume whenever we truly kill an Ascian (Nabriales, etc), we're also killing their innocent host (collateral damage, I suppose).

So then all the Warriors of Darkness were souls using other people's bodies, too? How else could they have killed themselves and transported to Eorzea and had any physical form?
And doesn't the same hold true for Unukalhai -- so why is there no comment given about the body he's occupying? Why is he welcomed by the Scions without anyone there giving any thought to the host he's using?

Maybe I'm misunderstanding what's going on with them? Are their bodies somehow their own, preserved across the worlds? If so, was this explained at some point and I just missed it?

[RobinMalvin]

Well here's my thought,

The bodies Ascians, WoD and possilby Unukalhai are not their own. They're able to exist as 'soul' without being absorbed to Lifestream because of the power of their crystals. The crystals can also apparently allow one to possess a living body as a host.

The way I understand this, once a body is possessed, there's no cure for that. The possessed person is either gone completely or tied to the possessor that if the possessor is purged, the host will die. Lahabrea threatened us with this last time, and we only managed to purge him and saved Thancred because of the Blessing of Light. The same with Nabriales' host; the host died after he was defeated.

[Anonymoose]

Clearing up a bit of context along the way:

(as well as voidkin like Succubi and Mindflayers)

Voidsent are essences incapable of life or death; their realm is void of all aether, including corporeal forms and a Lifestream. When they manifest in the corporeal world, it can be just by coming through a voidgate (a naturally-occurring or manufactured rent in the fabric of the world) and consuming enough aether to construct a corporeal form. They often do force their essences into a host and corrupt it from there, but it seems (to me) to be slightly different than what we're talking about the Ascians, since their souls are composed of pure aether to begin with.

every [Ascian] we see is actually an incorporeal being using the hijacked body (living or dead) <...> whenever we truly kill an Ascian <...> we're also killing their innocent host (collateral damage, I suppose).

In many cases, this appears to be true. Recall that we killed Nabriales's host and it actually showed him return from the Rift as an essence and destroy his own remains. And for some reason Lahabrea had Nabriales's sideburns in the fight with Thordan, either a highlight of his "new vessel" or some pretty obtuse foreshadowing. I assume that this is also incidental; if we just happened to come across Ascians between forms, we could still trap that soul in auracite. Alas, collateral damage seems to be frequent.

So then all the Warriors of Darkness were souls using other people's bodies, too? <...> And doesn't the same hold true for Unukalhai -- so why is there no comment given about the body he's occupying? Why is he welcomed by the Scions without anyone there giving any thought to the host he's using?

I had assumed the Warriors of Darkness might have been, but never let myself fully believe or disbelieve it. Once an Ascian possesses a vessel, it appears as though they're capable of traveling with it, even through voidgates and the Rift (Nabriales). It's possible that their original bodies were never destroyed in the first place, allowing them to retain them. When the Sahagin Elder gained immortality, we had to kill him the first time to see it.

That said, I definitely leave the door wide open for them to be possessing others.

I don't know why we ignore it, unless we just assume that what's done is done and people are constantly dying in the harsh realities of Eorzea, even just getting devoured by raptors while out picking pumpkins for dinner.

[Belhi]

Something to consider:

Its possible they also resort to using corpses. We see from the SMN quests that lesser Ascians aren't capable of possessing living hosts but can use dead bodies. Though we don't have any definitive proof or knowledge when the Ascian possessed the corpse, we see one wearing the body of a individual who would be dead for some time. Since he doesn't appear desiccated and no one describes him as corpse like it maybe that by possessing a corpse they can keep it from decay or potentially even rejuvenate it to a semblance of life.