From The Heretic Knowledge Vault
A mage of particularly great magical power. We've never seen anyone specifically identified as an arch mage, although it's reasonable to suspect that some of the faculty of the Sashi Mu Academy of Thaumaturgy and Conjuration would qualify. The only time we've seen them referenced, in fact, is here, during Ian Samael's attack on the Veracian Church. On that occasion, the reason the Veracians use the term is to assert that there are some things that even an arch mage can't do -- things that the Anilis-possessed Ian, however, proceeds to whip off like he's doing warm-up calisthenics. This is kinda scary when you think about it.