[ETA: Hope at 0:05: snerk. I never noticed that before.]
I've always had a hunch that there was a hint of Utena inspiration for the character. Someone at Squeenix evidently has watched the series, considering the sword-drawn-out-of-heart move in FFX (done by Jecht's Final Aeon, of all things.)
What really put me in mind of Utena was all of Lightning's rose petal imagery, which seems a little incongruous for such a badass. I noticed that Lightning's brand and her rose-shaped summons crystal appear just over the spot where Utena / Anthy draw their sword:
Of course, if the resemblance is not a coincidence, it's only superficial: Lightning is a heck of a lot more aware of the BS around her and is, on the surface at least, a cold cynic. She acts more like Juri than Utena.
I love the fact that Lightning takes Odin's sword and that she performs his Zantetsuken ("iron-cutting sword") finishing move used by that summons in previous FF games. And, hey, just noticed: Odin's horse-form has multiple eyes to make up for not having multiple legs in this iteration. Ah, FF and your creative mythology...
Also: does anyone have an animated gif userpic of Lightning kicking butt / smacking Snow?* I feel a need for a Lightning Smackdown icon to use when venting. (There's this old saying in chess: "When in doubt, push [a pawn]." I think Lightning's adapted it to, "when in doubt, punch the nearest blockhead.")
ETA: Goodness, what a rambling post.