Alright, time for the bonus part! This one is dedicated to the real bad of the game, Ultima. They aren't exactly a Dominant, but are a god, and have caused enough trauma to everyone, but especially the Dominants. There's a few things about their character that I'd like to talk about. So, without further ado, let's go.
Starting off by saying that, since they're a god, Ultima is believed to be just, and for a portion of the game, you are inclined to believe they are doing something for the sake of balance, if nothing else (turns out that isn't true). This leads me to the Esper Exodus from Ivalice, the Libra one, the literal balance. But it doesn't end there. You see, in FFXVI, magic and the sort comes from Aether, and that's what Ultima is collecting too. Exodus's element in Ivalice is Aether, and both divinities use spells of that element during their fights (that means the strong type of spells: Flare, Ultima, Scathe [in Exodus case at least], Meteor, that sort of thing). I found it interesting that Square would bring such elements to FFXVI, but I'm all up for it!
And while Ultima doesn't have exactly an element (well, essentially, their element is Aether, I guess), Ultima is also associated with darkness, if the fact they collect it during their fight in the Interdimensional Rift is anything to go by. That brings me to the fact Ultima is, for now, using Barnabas, Odin, the element of darkness itself, and how given that compatibility, Barnabas doesn't lose control like Dion does when Ultima controls him (fact which I'd already hinted at in my other posts). After all, darkness blends better with more darkness than with light.
Futhermore, while Clive isn't light itself, that's Dion, he is fire, which can still light up the world, plus he's the destructive side of it, so, given how Ultima was searching for a way to survive alone, it's no wonder they'd search for something so destructive, so unruly like fire to bring forth the end of the world.
Moving on, I noticed Ultima gains six wings during that final fight with them. Previously seen on Kefka and Sefiros (the latter with an extra one as a hand, but that's irrelevant here), six wings are associated with high order angels. All these three characters are gods, or tried to be (looking at you, oh almighty Sefiros), thus the six wings to represent that high station (and in Kefka and Sefiros cases also a reference to their game number, Sefiros counting the +1 wing he has as a hand). It's also interesting to note that all of them are angel like wings, not really demonic (Kefka for example did have a pair of demonic wings as a reference to the Devil from the Warring Triad he absorbed), which basically says Ultima views themselves as a pure being, no less because they're a god.
I don't really have anything else to go by for now. I did gave a quick look at Ultima's wiki page, and they mention how they reflect certain aspects of other gods in the series, like the Occuria, Bhunivelze and Ultima from Tactics, so that's pretty badass, I'd say. But I think I should really watch that 100% playthrough of 60 hours to be able to find more symbolism, be it arround Dominants or not.
Therefore, my posts are done for now. Mayhaps you have more information to add to what I have said, and if not, that's alright too. Perhaps in the future, I'll do that second possible bonus part I talked about.