So the cast is a group of summoners from an "exiled" universe that can use magic as if the player's library was their hand and milling out isn't a issue? Every turn a little more mana is added to the pool at a flat rate? What about the decks that depend on mana ramp to hit fast and hard? (ie mono-green elf deck.) How will you deal with players who want to claim their characters have access to over 60 cards worth of spells and lands, like the most basic anti-mill decks?

okay, that's enough questions for now. I love the idea.