I can finally get my thoughts out in a way that makes sense.
Hydaelyn and Zodiark:
Certain maniacs here called this one a long time ago, but it's good to see those cards finally laid out in a way that feels like a legitimate revelation. It may even set the stage for a third option: joining the Ascians is off the table for good (not that it ever really was on the table, per se), but we at least now know that it's possible to break from Team Hydaelyn (should we need to) without necessarily dooming the world itself.
The Originals:
This also made a lot of sense with what scattered pieces we have, as well as confirming what had been suspected about the nature of Ascian titles. It wasn't hard to guess that Ardbert was a part of the same soul, or that Emet-Selch saw something special in the WoL's soul. That something apparently being a more-complete-than-usual soul. Is that the true nature of the Echo?
The Exarch:
Man, was that a long time coming. I spent most of the MSQ worried that they were bringing back and killing off the artist formerly known as G'raha Tia in an arc totally unconnected to the Allagans, just for irony points. The premeditated sacrifice schtick wasn't hard to predict, especially from him, and for a while I was sure that FFXIV was back off its meds, and that his little monologue about wanting to go on adventures with his hero was just to make him Haurchefant 2.0. Godsdammit was that 79 scene too much for my heart.
But the ending, and all the little choices they worked into it, finally communicated to me that they cared. That smile made the past 5 years of waiting worth it, as I had only sometimes let myself hope it would. That is the only kind of use of "Eternal Wind" I will accept. So, at long last, thank you, Yoshida.
I will, however, have to keep calling him "Exarch", as it seems the name G'raha Tia is being held in reserve for someone else after all. I had suspected from his introduction that Exarch could open the Tower on the Source, but not that the story would actually acknowledge that. And yet. I have a feeling that doing so will be what severs the link binding him to our timeline, but that, I think, is the one sacrifice he's allowed to make. (Though it will be bittersweet as hell, especially after our adventure together.)
As for easter eggs relating to the above, you can shoot him during both Dwarf minigames. Also, you can take the Wind-up G'raha to him for a cute little bonus scene.