This is an excellent short piece. You pack your phrases with meaning, which is a good strategy for writing drabbles, I think.
I love that the weight of time is more solid than the earth on the road to Zanarkand.
The phrase about the pyreflies reminding Yuna of her impending death is also absolutely brilliant.
The only thing that bothers me slightly is this final line: "Tidus calls to her, shaking her out of her reverie, and she turns to face whichever of the thousand fates that awaits her."
It's the phrase "whichever of the thousand fates that awaits her." I may be completely wrong, but "whichever" just makes me pause. It seems awkward somehow. I would change it to read "the thousand possible fates that await her." That seems to leave it more open, somehow, but since I can't seem to explain precisely what it is about that phrase that doesn't seem right to me you may certainly (as always) take that with a grain of salt.
Still, this is a beautifully evocative short piece that I really enjoyed reading.