EvilWall is tough, thats for sure. Unless you're overlevelled, but you probably aren't if it's your first time through the game.

Bio is a must. Bio it, then berserk and haste at least two of your fighters. (You'd be surprised how much damage you do!) Try using slow, but I'm not 100% sure it would work. Rydia should be summoning Titan, or Leviathan if you got him already, but you most likely did not. Titan will do if not. After Rosa berserks/hastes, have her heal the party. Keep at least one melee fighter not berserked, probably Kain. You can have him Jump if you want. Just revive fallen party members with Phoenix Downs (Lifes?...)

If you don't have some of these spells, just level up in the cave. If you were killing all of the TrapDoors, you should have gotten alot of Exp. already. I believe Rydia learns Bio it at level 30 something... maybe the same with Rosa's slow, haste, and berserk. Does anyone know the levels they learn those spells? I don't remember...

Wasn't there a thread on this? Meh.