Since the ancient times, people believed in the supernatural, anything that they could not explain with science or logic concurred to that category. A man made the difference and gave to the human kind the ways of magic. That man was named Kerbech and he was one of the Ancients. Who or what he was is a different chapter, fact is that he used his occult knowledge to pass down to his two disciples the method of elemental enforcement aka magic.
Kerbech's method of invocation was not the same with the sorcerers of the East (then known as shinobi). The eastern people pleaded the elementals to convert their own soul force energy into their desired element that they had a certain affinity with, via seal casting. Kerbech's method was quite different, he forcefully drew elemental energy from his environment or the dragonic entities of his surroundings via using as a coin his own, without the need of a certain elemental affinity. Kerbech had mastery of the Five Basic elements, Fire-Water-Tree-Wind-Rock and their combinations, Meteo-Thunder-Silence-Sand-Firestorm.
One may ask why are they called Mage-Blades? The answer is simple. They are not simple spell casters, they are warriors that use magic to overpower their foes. They enchant their arms, turning simple spears to thunderbolts and shields to impenetrable barriers. They use armed combat combined with their elemental strength destroying all obstacles.