Phantom Beasts are illusory monsters. Their magical attacks can pierce any armor and deal overwhelming damage. Unfortunately they are easily destroyed.
Summon - Unit was summoned and belongs to another world.
Construct - Unit is immune to Mind and Death effects, poison, critical hits, Gaze attacks and Positive and Negative energy. They cannot be raised from the dead.
Ethereal - Unit's attacks ignore armor (are more likely to hit).
Illusion Immunity - Unit is immune to illusions. It can see invisible units and illusory attacks do not ignore its armor.