Void Magic: In the olden days, base elemental magic was the only magic known. Manipulation of Fire, Water, Air, Earth were the common. 'Void Magic' was the moniker given to non-standard abilities that arose as general understanding of magic advanced and new abilities were discovered. These abilities were generally seen as 'unnatural' and, in extreme cases, downright 'evil.'
In modern times, the term is still in use, but the meaning has changed. It is now a blanket term for all magic not yet understood, especially by the person speaking, though it's generally only used by laymen. Has slight negative connotations.
I put this under a picture of Bastian for no reason in particular.