@Scout - There are only humans. Magic is rare in the sense that very few people are born with the innate ability to tap into it - down to the fractions of a percent. I do plan on expanding lore for everything, but truth be told some of the places we're going to are literally only a name to me as well; Im trying to make this an organic experience, one that helps get my own creativity flowing as well as everyone else's. So with the League, think of a weird mix between ancient Greece and modern America - highly commercialized, independent, sometimes self-righteous, argumentative, and greedy. And yet they possess a kind of optimism that seems impossible to possess, able to take a loss and roll with the punches.

@Hank - Perfect. In fact you nailed two particular spots on the head before I even got around to clarifying them (on a mage's graduation, and on demonic possession and the interaction with a Null).