i beat her on my first go around. however, i was at lvl 100 and most of my other people were at 87-95 (except for irvine and selphie). when she's juntcioned to her GF she kills yours when you try to summon them, so its wasting valuable attack time trying. (SPOILER)there are 4 stages to the final fight (5 if you include when griever loses his tail) it takes practice, and a few visits to the islands closest to heaven and hell.