Ferne
called ghosts Ashkin back in the day when we only had Bogy/Revenant ghosts. The
Revenant Things FATE backs this up, saying that these are souls unaware of their death, unreturned to the lifestream, lost and violent. The names of most of them imply these circumstances.
Corrupted Nimians were taken by the tonberry sickness,
Betrayed Souls were killed by heretics in the Darkhold,
Poisoned Peasants succumbed to the noxious fumes of the Aurum Vale. I can make excuses for a lot of things. Some mobs get accused of being from the Void when they're not. There's a dormouse in the Shroud named Deepvoid Deathmouse just because Gridanian's think it's unnaturally big. Maybe we can hit ghosts with a sword because aether gathers around the unsent soul and that's why it's a corporeal blob. Maybe it has an unnatural circulatory system with a little bit of blood we can beat out of it. But why does the ghost drop
Voidsent blood when it's, as far as we've been told, an Ashkin?
Devil's Advocate? Maybe the Bogy/Revenant is a creature of the Void and never had anything to do with our Eorzean dead in the first place. Maybe the names of the ghosts are just as misguided as the name of the mouse. Wisps are confirmed as being from the Void and Eorzeans believe they, too, might be the souls of the dead.
Barring a lore nuance that I've overlooked, I believe the ghosts may be an oversight - a mistake. I still don't think SE would willfully misguide us about game mechanic basics. If anybody's wrong, I'd expect it to be Eorzeans. This leads me to believe that
Eorzeans may be mistaken about the mouse,
Eorzeans may be mistaken about the wisps, and
Square Enix may be mistaken about Ashkin ghosts coming out of a Voidgate and dropping Voidsent blood. Especially in light of...