Blue Mage has a spell called "Aetherial Mimicry" that is learned from the corruption enemies fought during the first boss of Pharos Sirius (Hard).

However, the corruption enemies use "Aetheric Mimicry," as shown in the picture below.



I understand that "Aetherial" and "Aetheric" have the same meaning and are both used throughout the game, but it should be consistent here since you are learning the spell from the corruption.

On a lesser note, in the Japanese version, the Blue Mage spell and the corruption's spell have the same name.