
Originally Posted by
Warlock
Spoilered so that it's easier for me to scroll.
"Dawn may banish even the darkest night."
This may be referring to the coming Astral Era that will begin after the Seventh Umbra Era. Since we know Umbral Eras consist of times of destruction, and end when they're over, I think it's reasonable to assume that Bahamut's attack was the Umbral Era and the Seventh Astral Era began when he was locked away.
"Yet ever shall primal desires burn."
I think the 'primal desires' line may be a bit of a double entendre. I don't think they'd just use that word in that sense, when it could also mean something different in the context of the game. With that in mind, I think this line is suggesting that the Primals are still around and the beastmen are still fighting over the crystals.
"Two swords vie to lay them low— A blade born of light, and a blade forged of might."
I'm not so sure about this one, but I think these may refer to a division between the people of Eorzea's ideal methods of dealing with the Primals and Bahamut. One side seeks out the power of the Twelve, while the other turns to the Empire's Magitek. But, that's not all, I think this line may also refer to the 'swords' or 'keys' that sealed Bahamut. The blade of light would refer to the Twelve's version of the key/sword, in which they attempted to seal him with their raw magic alone, whereas the Sharlyans used their Magitek, their blade of Might, to seal him succefully.
"Alas, man may entrust his fate unto but one."
As for the final line, it think that is self explanatory. In the end, only one of the two methods will work. Personally, I'm hoping for the Twelve to help us, but I feel that Louisoix is referring to Magitek. He's seen first hand how The Twelve's power failed, so it would be logical to assume he decided that their last chance is to use Magitek to stop Bahamut, as that worked before.