Black Market Tycoon

Treasure generation without a sacrifice cost is normally the drawback: a token that only matters when you cash it in. This inverts the math. The tap ability builds Treasures for free, but the upkeep trigger deals two damage to you for every one still sitting on the battlefield, which means the card is punishing you for hoarding the very resource it hands out. That tension is the whole engine. The ideal line is to spend each Treasure the turn you make it, treating the tap as a mana-fixing and ramp valve rather than a stockpile; leave them lying around and the body becomes a clock aimed squarely at its own controller. It rewards decks already built to consume artifacts before upkeep comes back around, since anything that eats Treasures (sacrifice payoffs, affinity-style artifact counts, cost reduction) clears the liability off the board. The self-inflicted damage scales with exactly the thing the ability produces, so there is no safe passive mode: you either metabolize the wealth or it burns you down. A creature that makes mana on demand across two colors is genuinely useful; the upkeep clause is the leash that keeps a free ramp maker from being a strict upgrade over the countless Treasure-producers that ask for a sacrifice instead. Because the drawback is damage rather than life loss, it is technically preventable, but the whole design assumes you will not need to: you empty the board first. Left idle, it is slow suicide. Fed into the right consumption loop, it is ramp that pays no toll.