Demon Wall

It is the last wall of defense in the Sealed Cave after getting the last Dark Crystal. This battle must be won quickly, as the Demon Wall will constantly close in on you and the party, and when it gets close enough, will start to use an Instant Death attack called Crush. You should immediately inflict Slow using either Spider's Silk or the Slow spell. Rosa should cast Berserk on Cecil, Kain, and possibly Edge if you choose not to use his Throw command. Rosa can then heal, or revive them with Raise if the Demon Wall uses its instant death attack. Assuming you has been to the Sylph Cave, they could equip Cecil or Kain with the Avenger sword. Not only does it put them in Auto-Berserk, saving Rosa a turn and increasing damage output, it also increases their Strength, Agility and Stamina by 10. Demon Stuck in a Wall. Slowly moving closer to Squish you.