Hama, the Bloodbender

Blue-black has always turned an opponent's graveyard into borrowed spellbook space, but the borrowing usually comes with a catch: cast the stolen card once, and it moves to the stack and then to a graveyard, spent. This design keeps that fundamental limit intact while rewriting the payment method entirely. The mill three, exile one clause is the setup; the interesting part is how the exiled card gets cast. Instead of paying its printed cost, you waterbend for its mana value, a convertible cost that lets you tap artifacts and creatures for a generic each. That does two things at once. It strips the color pips off the stolen spell (a red or green noncreature card casts just fine off a battlefield of tokens and mana rocks), and it converts board presence into casting power without ever holding up colored mana. The theft never becomes a loop, though: once you waterbend the exiled card, it leaves exile the same way any cast-from-exile card does. The engine is a one-shot conversion, not a rented flashback that fires every turn. The 3/3 body is almost beside the point, except as the leash: kill the Warlock before you spend the exiled card and it strands in exile permanently, which is the fragility the design accepts in exchange for letting you tap a whole board to pay a spell's whole cost.