From Final Fantasy Wiki
The Destroyer is an enemy in the game Final Fantasy VI. Like most enemies in the Magitek Research Facility, it has high defenses. This, combined with the fact that the Destroyer has no real weaknesses, makes it difficult to defeat. Thankfully, their attacks are weak. They will try to cast Life 3 on occasion, but will fail because they only have 35 MP, and Life 3 costs 50 MP. Luckily, this makes the Destroyer useful as a Rage, as this allows Gau to cast Life 3 early on.
[edit] Related enemies