[@Raijinslayer]: Unfortunately I don't think that would work out too well. While you could summon spirits, mystical beings are not at the beck and call of anyone for the most part(though there's so much variation it's hard to go through and say so for all of them). Dragons, though, definitely are off the plate. While you technically [i]can[/i] have an affinity related to them, they're from space, made of the same material as stars, and are reality's tool to destroy threats to it.

[@The Omnipotent Sphere]: Well, the Circles are like magical colleges combined with sort of... I guess mage offices/research centers/police forces? A lot of magi go to a circle for formal magical education, but they also have a lot more to them then just that.