Where did the Antica come from that the Galka developed this whole civilization on the continent before being forced out?
Where did the Sandworm of the past dissappear to that it is not only never mentioned in the present, but also doesn't show up?
What happened to the Fae?
And the biggest for me, what were the original plan for Demisang Deleterious? Writing an entire system to randomize its armor can't have been an accident, so what was the actual intent there?
This is just the best take I've got thinking about it really hard while I take a too much beef this week poo:
So all of the races on Vana'diel as far as we know are descended from the destruction of Paradise and Promathia. Further still, some of them were mutated by The Meltdown(the event that came at the destruction of the Crag of Vahzl perpetrated by The Kuluu). I assume this includes the Beastmen, even the Antica, because they all have humanoid shape (two legs, two arms, a head). While the Kuluu were explicitly mutated into Tonberries, there is no precise exposition about what The Meltdown did to other races.
So I think the Antica were a race of humanoids that were mutated into ant people, and that they burrowed deep into the sands being rather completely unknown by the rest of the world until the Galka dug too deeply, awakening them from self imposed stasis. Like how ant hills go dormant in winter, the Antica went dormant deep under Altepa until the aftermath of The Meltdown was over. The Galka digging too deeply was the clear call from the outside that let them know the surface was OK again.
Now obviously, that creates more questions, chief among them being, "If they survived The Meltdown's immediate effects, why burrow to avoid them further?"
Way simpler answer that doesn't try to capitalize on RoTZ lore is just, they were always there deep down, and didn't know about the surface at all until The Galka dug too deep. Or perhaps The Zilart had sealed them at some point in the past, and then the Galka dug too deep.
That's all I've got!
Re: Sandworm
We killed it, duh!
Re: Fae
Well, given Witchfire Glen's proximity to a Veridical Conflux that goes straight to The Walk of Echoes, and that the past is technically a Vana'diel Prime of sorts, and then given their presence in Abyssea, it could be that The Fae are from somewhere else and slipped into the WoTG era from another reality.
Re: Demisang Deletrious
Fomors have always given me the vibe of being PVP in PVE clothing. I think the original intent of a randomized armor and weapon may have been the starts at an attempt to have a battlefield consisting of dozens of randomized Fomors as a sort of, "Can you beat the dark version of your own party?" or something like that. But then, I don't think that D.D. is actually truly randomized. Granted, I have not run Sortie as much as really anyone else who is still even semi-serious about XI, but for me, he almost always has Great Axe and then a hodgepodge of WHM and WAR AF. Sometimes there's some variety in this. I've seen Great Axe, Dual Daggers, Dual Swords, Staff, Club and Shield, and Hand to Hand. So he's what, based off the 6 starter jobs but restricted to being melee? Maybe that's just how they kept with the theming of the Sortie Fomors being largely in parties.