The Demon is an enemy that appears in Crisis Core -Final Fantasy VII-.
This enemy boosts its defenses by casting Barrier and MBarrier on itself. It casts Death to instantly kill its opponents.
When facing the Demon, Zack should be sure to have accessories equipped that protect him from Instant Death. He can break through this enemy's defenses by using the Dispel or Dispel Blade materia.
demon is "an evil spirit or devil, especially one thought to possess a person or act as a tormentor in hell."