Slobad, Goblin Tinkerer

Indestructibility on demand, paid for with artifacts you can spare. The strategic axis is the swap: with a removal spell pointed at your best artifact, sacrifice a worthless one to make the target indestructible, and the destroy effect still resolves but simply does nothing. The ability has no timing restriction, so the same trick works against a sweeper: hold up a piece of fodder and an incoming board wipe rolls off your chosen artifact for no mana at all. The 1/2 body courts no combat (this is an engine, not a clock), and with no mana cost on the activation, the only real ceiling is how many artifacts you can afford to throw into the furnace. The Goblin Artificer treating his own machines as ammunition is a flavor read that pays off twice, because the sacrifice clause is just as comfortable feeding a death-matters engine: every artifact you offer up is a trigger waiting somewhere else on your board. That dual nature is what has kept the card relevant past its protective headline. The indestructibility is the pitch; the free, repeatable artifact sacrifice outlet is the part that keeps finding new homes in decks that never cared about protecting anything at all.