Sokenzan Smelter

The trade is the whole engine: a spent artifact becomes a 3/1 with haste, every combat, for one extra mana. That conversion rate plays better than its rate line suggests because the input is meant to be something you were already finished with, a Treasure you had been sitting on, a self-sacrificing piece of gear, a token you had no further use for. Where most sacrifice payoffs feed permanents into a drain effect or a card-draw trigger, this one launders them into repeatable board presence: a fresh attacker that arrives ready to swing, no summoning sickness to grind through. The Construct token is the all-offense body, a 3/1 that trades up in combat or dies to a stiff breeze but does not need to survive to have earned its keep. Because the ability fires at the beginning of combat on your turn, that Construct hits the battlefield attack-ready before you declare attackers, turning each turn's leftover artifact into that turn's extra damage rather than a one-shot burst. Build a deck that spits out artifacts as a byproduct and the 2/2 Goblin body stops being the point entirely: the Smelter becomes a conversion machine, recycling spent resources into a clock that reloads on its own.