Half Magi is an expression. one magic user is a mage two are magi. This is the closest i can come to a proper word for these individuals. These people show extraordinary skill in the path they have chosen Weather it is because they themselves are magical,Chosen to do this sort of magic or are overly skillful I do not know. what IS clear to me is that these persons show abilitys not often shown among users of that type. i.e entering minds Being magically summoned being able to create complex illusions or simply cast bigger and better than the rest. other means may be how hard the person has trained or prolonged exposure to Magical fields or items.
As Above magi are people who show extraordinary amount of skill in Their Arts of magic. Their are so far only three Catagorised Types of magi. Light ,Dark and Arcane. below are a few Suspected Magi.