In Winhill it is said that Ellone was in a festival and they liked seing her prancing like an angel.Squaresoft didn´t create this dialogue at random.
It is to show that the angel which appears at Ulti´s time is Ellone.
This angel looks like a fairy over our characters,a concept associated with Ellone.
And I also believe it to be Rinoa.
This confirms my Rinoa=Ellone theory.
Also following this logic it´s easy to see that Julia=Ultimecia as I argued previously using other arguments.
So basically this battle is a "evil witch versus magus with the help of good faeries"fight.