Aboroth

A 9/9 for six mana that pays its rent in its own flesh: this is cumulative upkeep turned into a self-destruct timer, and the mechanic is the whole point. Most cumulative upkeep cards drain mana or life over time; here the cost is paid in -1/-1 counters, so the creature is on a fixed schedule of decay no matter how much mana you have. First upkeep costs one counter, the next costs two, then three, and the math accelerates until the body collapses under its own -1/-1 counters. The design encodes a brutal honesty: you get an enormous attacker now, but the card itself is counting down to its own funeral, and there is no paying your way out of the slide. The tension lives in the gap between cumulative upkeep's intended pressure (each turn the permanent grows more expensive to keep) and a payment that actively shrinks the asset you are trying to keep. That makes it a creature you want to cash in fast, before the counters stack high enough to erase the stat line that justified casting it. It belongs to Weatherlight's broader experiment with cumulative upkeep as a balancing lever on oversized effects, a mechanic the game has largely retired because the bookkeeping outpaced the payoff. Among the purest distillations of the idea: raw size, rented at a rate that only ever gets worse, with the body itself serving as both the asset and the currency.