my suggestion use armarant and by zidanes strongest weapon you can buy. buy 10 or so and throw them at ozma for an easy 9999 every time he's only got baout 56000HP so it shouldnt take too long ahve eveyrone else focused on keeping your guys alive. and by the way my armarant was only on lv 38 when i beat ozma so dont worry much about leveling him up.

oh and i dindt find all the friendly monsters its not needed.