Thanks for the French Translations Vil!It really helps to see that Corguevais is pretty much a pawn for the scheming trio.
Re: Greinfarr.
It does appear that he got his glory after the sordid affair of Niellefresne. He's a hero by the time you get into Ul'dah. Greinfarr, in the association of Niellefresne, was talking like he was happy to be exiled because of his poor behavior. Looks like the murder of Nielle made him sit up a little straighter and cooperate with the establishment.
He also appears in "Struck through the Heart" in an echo. You see him kneeling over Niellefresne and listening to Coulberneaux talk to him about Lolorito guarding the hearstrike. After he admits to not being able to stab his brother's body to end his stasis, Greinfarr says that Nielle was his friend and he would do anything for him.
That annoys me because he didn't stop Nielle that day when he had the chance because he was too scared or something, sending Thancred to do it.
I don't think Ascians are the great danger in the Ul'dah questline. They don't make an appearance at all. There's no primals for them to be chasing after. And the horn used to shake the Goobbue awake doesn't appear to interest them.Also when you mentioned that "something much worse than the Empire" was coming, that seemed to be a pretty obvious (well, after the fact anyway) foreshadowing of the Ascians. Ferne
My only theory is that it relates to the original Dalamud story. The red moon was going to have another purpose outside of Bahamut. In other Final Fantasies, the Crystal Tower is directly related to the awakening of a dead mage or king that has been sleeping/dead a long time (FFIII). Another references to sleeping/dead powerful people also reference moons and meteors ((FFIV)).
Warburton, Corguevais and Ascilia all flee to Ul'dah to warn them of the Garleans coming. Why would the Garleans bother with Ul'dah? Thancred says that it's related to the fact that they are perfecting a means of resurrecting the dead. But why would they care? Well, if Ul'dah caught wind of Meteor's magic, they might try and resurrect the old mage/magic themselves and use it to rule over and even possibly to destroy the entire Empire. That would certainly make the Garlean's very irritated. The "Garlean Spy" then would be working to prevent them from ever using that ability and/or claim it for themselves.
When the seal is broken over the falls and the primals are released, you see those dark clouds and the meteor shower occur for the second time. Erik, the NPC fromt he Monk Quests, tells you that silvertear falls is very close to the the tomb of Xandes (aka the Crystal Tower) itself and that the chaotic state of the aether in Mor Dhona is the the result of the Tower, not the ceruleum explosion that released the primals (Note that the aether in Mor Dhona is purple, not the usual blue.) The Empire may have gone there in an attempt to find the tomb and gotten more than they bargained for.
Because these things are kinda happening at the same time, there's a possibility that they are connected. Exactly how will have to be confirmed some other time.