Put on your tinfoil, I've got some theory.
When someone dies, we know their soul moves on to the Lifestream, i.e. the circle of life/death/return. If what I remember about corpses needing to be tended so as to not rise (I sincerely wish I could remember where that came from) is true, and we combine that with what we know about the Voidsent (that they are always looking for cracks and pinholes in our world to slip through with) then... Well, the absence of a soul might makes for a pretty damn good pinhole.
Imps hang out around places where the dead are collected. It's probably something more complex than "quick, bind his hands so zombie Jim can't claw out of his coffin" but if you've got all of these corpses lying about, all of these canisters drawing the void to one place and all of these demons trying to slip through, it makes sense that we'd often see the Void and the Dead in the same places. Hell, I'd even go so far as to theorize that Avere's half-ahriman appearance is due to the fact that he's been dead for so long and Edda brings him to such a void-dense place (Tam-Tara being a place where the dead were kept, and some of those guys have been dead for a long time). It makes sense that such a tasty locale would harbor some of the stronger voidsent, and Avere's transformation just might have been something finally slipping through that pinhole.
Edit: Second theory: A soulless corpse might not be a pinhole, but it might be easier to control a dead body than it is to actually break through the barrier. We've seen through the THM questlines what voidsent possession looks like. Imagine that without a soul or a consciousness in the way to stop something malevolent from trying to control your body! Voidsent want to come through to Eorzea, but in lieu of that, why not do the next-best thing and just control something already here?
When someone dies, we know their soul moves on to the Lifestream, i.e. the circle of life/death/return. If what I remember about corpses needing to be tended so as to not rise (I sincerely wish I could remember where that came from) is true, and we combine that with what we know about the Voidsent (that they are always looking for cracks and pinholes in our world to slip through with) then... Well, the absence of a soul might makes for a pretty damn good pinhole.
Imps hang out around places where the dead are collected. It's probably something more complex than "quick, bind his hands so zombie Jim can't claw out of his coffin" but if you've got all of these corpses lying about, all of these canisters drawing the void to one place and all of these demons trying to slip through, it makes sense that we'd often see the Void and the Dead in the same places. Hell, I'd even go so far as to theorize that Avere's half-ahriman appearance is due to the fact that he's been dead for so long and Edda brings him to such a void-dense place (Tam-Tara being a place where the dead were kept, and some of those guys have been dead for a long time). It makes sense that such a tasty locale would harbor some of the stronger voidsent, and Avere's transformation just might have been something finally slipping through that pinhole.
Edit: Second theory: A soulless corpse might not be a pinhole, but it might be easier to control a dead body than it is to actually break through the barrier. We've seen through the THM questlines what voidsent possession looks like. Imagine that without a soul or a consciousness in the way to stop something malevolent from trying to control your body! Voidsent want to come through to Eorzea, but in lieu of that, why not do the next-best thing and just control something already here?
![[Image: yEROfKO.png]](http://i.imgur.com/yEROfKO.png)
