First I ought to excuse myself for disapearing into timeless mist twice in a row. I think I should make a habit of declaring when I go to sleep, when I engage with somebody in a discussion. Instead of disapearing on you. 
Well then lets talk magic. One magic I'm currently thinking about, because I like contracts so much, is rituals and summonings. Where one can call upon a magical being to do your work.
My take on it them would be, that these beings don't have "magic" besides the ability to peer into neighboring worlds and to cross into those worlds. Well the stronger ones have incredible multitasking skills. So everthing "magic" is just transdimensional beings doing their job. A barrier? Just a dude blocking the way. A floating platform? Same dude holding it up. An alarm ward? Just another guy standing guard.
There are "magics" for anything, because there's an endless stream of unemployed demons, fae and whatnot doing those things. A mystical service industry!
So @Candlebite, what do you think of this idea? Do you have something to add to this concept, or a critique?