I'm guessing you don't have materia, right?

You could equip Cloud with Yoshiyuki and kill off two party members. It will do insane damage, but it's risky.

More conventional strategy is to move everyone to back row and use items on it. Induce Fury on party members to build up Limit Gauges faster, or better yet, enter the battle with full Limit Gauges and release.

There's not much you can do about Aero3; it usually hits for about 90-110 percent of my health at that point.

Of course, if this is Disc II, it should be a cinch, because you'll have extra materia that Yuffie hasn't stolen.