Well, you have to remember the very term 'voidsent' means literally 'from the Void', but is usually meant to refer to something 'not of Eorzean/Hydaelyn origin' - the
Void being the 'world between worlds' that has appeared in multiple FF games (specifically FFV). Gilgamesh specifically was cast into the Void at the end of FFV and became a traveller of it, using it to travel to other FF worlds (like FFVIII and XII and.. of course... here in FFXIV), so... on one hand... the term 'voidsent' could
potentially mean a creature from another world.