Hints on beating emerald weapon
right. number one, dont use knights of the round table, as you can get 3 attacks in the same amount of time, and with everyone having 4 cut, you manage about 360,000 to knights of the rounds 120,000
second, if you use wall on all three, and stand them on the back row, you should, providing your defence is high enough, avoid the 9999 damage to all three characters, with them each taking about 9000-9500. after this happens, use a megalixir, and you should be fine
finally, you'll never win unless you have mastered the phoenix and final attack materia's. two mastered double cut materias and a third on X4 cut will help alot as well, as the battle goes much faster, and you have a much better chance of winning