Quote Originally Posted by Erudito View Post
Correct me if I’m wrong, but didn’t Minfilia’s body turn to aether/vanish when she pledged all of her being to big momma crystal? Perhaps returning in a smaller body is easier, uses less aether.
I've just been back through 3.1-3.3 in the past week or so, and took a different alt through 3.4 a few months ago. After the Antitower (quest: "Word of the Mother", cutscene 2) when you first see Minfilia as the 'Word of the Mother', at the end she struggles to hold her form and seems to shatter and vanish. But then you get to 3.4, and Urianger pulls his grand scheme to get you and the Warriors of Darkness together, which somehow causes your crystals to channel energy to Hydaelyn and you all get warped to the aetherial sea.

"One Life for One World", cutscene 4: Minfilia appears again and says that because of the extra strength Hydaelyn has gained because of this, She has been able to set Minifilia free to act as Her emissary to the First Shard. (It's implied that she's basically an anti-Ascian at this point - the title of emissary suggests a direct opposite to Elidibus.) To save that world, we are told, it may be necessary for her to remain there forever.

And yet as she departs...

MINFILIA

'Tis a strange feeling. So many times have I watched you depart, my heart filled with worry, and yet ever did you return to me in triumph.

Someday, when I have found a way to free this star from Her sorrow, I promise you I shall repay the favour.
We watch her go, afraid that we may never see her again. But someday, she promises, she will return to us in triumph. That's the sort of promise that tends to get upheld in a story.

It doesn't sound at all like a permanent farewell to me.