What great speculation thread everyone.
I'd like to point out the balancing of the "force" as well. Up until 3.1, we think of the Warrior of Light as part of the Scions and he/she is the counter point of the Ascians, but with the introduction of Warrior of Darkness, we start to see how the "chessboard" is like. So far, it seems like we know, despite whatever philosophy or grey area there might be, there are these opposing forces:
Hydaelyn vs. Zodiark
The Scions vs. The Ascians
Warrior of Light vs. Warrior of Dark
Now, if you think about the Ascians, they are a powerful force. We (at least I) don't know where they got their power from. Assuming it's from the Zodiark itself, comparing to them, the Scions are nothing. Will it be far fetch to think that Minfilia is finally receiving her "power" that is equivalent to the Ascians to counter that, regardless of whatever path that got her there (ie: people has been suggesting if she volunteered or not.)