Lulu's Overdrive + Trio of 9,999 =

Anyway, no, I don't think Yuna's is useless, unless you already Overdrive your Aeons beforehand. At least you can save it for when that Aeon uses up its Overdrive, or something. None of the Overdrives were useless, unless you hate Blitzball and never got the better ones for Wakka.