Bag of Devouring

A treasure chest that eats its own hoard before letting you take anything back. The design turns a familiar shape (a sacrifice outlet that draws cards) into a gamble with an escrow account: nontoken artifacts and creatures you fold into it get exiled after they hit the graveyard, and the only way to recover them is to cash out by sacrificing the chest itself and rolling a d10. That token exemption carries real weight, because the engines most eager to feed a draw-on-sacrifice outlet run on tokens: those you can loop freely, so the chest quietly draws a line between fuel that gets banked and fuel that gets consumed for cards. The cash-out is where the tension lives. The exiled pile grows every time you feed it a real permanent, but the return is capped at a single roll, so a hungry mid-game hoard can bank far more than the die will ever hand back. It punishes greed structurally: overfill it and you are trusting a d10 to recoup a stack of material, while a modest three or four cards exiled makes the return closer to a sure thing. And the exile clause is a quiet knife against your own recursion, since anything nontoken you commit is gone until you pay to gamble it back rather than sitting in a graveyard you could otherwise mine. It asks you to sacrifice the value engine to collect on the value, and to guess correctly about when the pile has grown too big to safely reclaim.