The Power Head is an enemy in Crisis Core -Final Fantasy VII-.
Just like any other robotic or machine foes, Power Head is vulnerable to magical attacks. However, do not attack it with Thunder-elemental attacks as it is immune to Thunder. Use Fire or Blizzard to inflict significant damage. Be wary when dealing with many Power Heads, as they can reduce AP and MP with their attacks, as well as inflict Silence and worse, Stop.