Ancient Stone Idol

The cost reduction is written as a reward for going wide, but the real trick is the timing keyword bolted onto it. Flash means the reduction reads off attacking creatures, so the discount comes due during the declare-attackers step, when the board is already committed and the attacking player has swung with everything. Cast it in the middle of an opponent's alpha strike and a 12/12 trampler lands as a surprise blocker: the ten-mana sticker price drops sharply against a wide attack, shedding a chunk of its cost when four or five attackers are already tapped and pointed at you. That is the design's whole personality. It punishes the go-wide plan by turning the attackers themselves into the thing that pays for the wall. The death trigger closes the loop: kill the 12/12 in combat and its controller is handed a 6/12 Construct with trample, a body that keeps blocking and keeps threatening on its own. So the card resists the two clean answers to a huge threat at once. Remove it and you feed the replacement; race it and the flash blocker eats your attack before you can. It is a defensive haymaker dressed as a mana-cost joke, built for the multiplayer tables where somebody is always overextending into open mana and never quite believes the pilot has the payment sitting behind an untapped board.