Krark-Clan Stoker
Trading an artifact for two red mana at a one-for-one rate is a strange way to ramp, but in a deck overflowing with cheap artifact filler the conversion runs cheap: a spent Ornithopter or a depleted piece of equipment becomes a burst of red. The part worth noticing is the timing. Because the ability is instant-speed, the 2/2 sits on the board as a held charge, mana you can release in response to a counterspell, to bluff a combat trick, or to solve a combat-math problem rather than committing it at sorcery speed on your own turn. The tap symbol is what meters it: one activation per turn, not a chain. That single line is the whole difference between this card and Krark-Clan Ironworks, the noncreature engine that sacrifices artifacts in bulk for an explosive storm turn. The Stoker offers the same exchange parceled out one crack at a time, with an attackable body attached: a Goblin Shaman the rest of the tribe registers, a creature that can block or swing in between activations. The cost is harsh in a vacuum, since you are feeding your own permanents into the engine, which is exactly why it only reads well in a shell already happy to lose its artifacts. A slow drip of burst mana, built for a heavily artifact-laden era, for decks that want to convert spent permanents into a single relevant activation.
