Thread isn't tagged for spoilers, so gonna put this in a hidden block:
We learn from Minfilia that there's three "states of being" for lack of a better term: the corporeal realm, the aetherial realm, and then this state of limbo that's in between. When people die, their aether is released and goes to the aetherial realm. When people are born, aether is returned from the aetherial realm to give them life. Apparently the Ascians know a "trick" (and according to Elidibus, Echo users, when able to fully utilize their power, should be able to do the same) that allows them to float their aether in limbo until they find another suitable host in place of their physical body that was just killed. (or they just decided to transfer out of)
Anyway, not sure why I wrote all that up now. It was pretty interesting to learn, and now the Scions need to find some kind of device, like the darkness crystals, that can trap the Ascian's aether before they're able to manifest into another corporeal form.
Near the end of the main storyline we see this realm (which I assume is the limbo area for the Ascians, or the Void perhaps) where the twelve (I still think there's a real connection here with Eorzea's gods...) Ascians + Elidibus are convened to discuss the going ons of the Primals and such. With Ramuh's defeat there's only one Primal left. Until 2.4 comes we won't really know what Shiva's intentions are. Right now she's doing very little than sending out raiding parties of Ishgardian heretics, so we don't even know which beast tribe (if any) is associated with her. If Shiva is defeated, will the Ascian's grand plan come to fruition?
We also see that the Ascians appear to be running the show in Ishgard, which adds a new layer of complexity to the heretics that are devoting themselves to dragonkind's cause. The Ishgardians have all but withdrawn themselves from the going ons of the lands outside of Coerthas. Makes you wonder if the Ascians had a hand in keeping Ishgard from entering the Eorzean Alliance pre-Dalamud's arrival, or if it's been going from even long before then.
Lots of things were touched on during the main storyline this patch, but it just tends to leave even more questions. Can't wait to see what 2.4 brings us. Obviously things aren't quite tied up with the Ul'dahn Syndicate member yet. While I feel it's kind of early in the game for Omega Weapon to surface, that'll definitely be something to look out for.