Liquimetal Torque

The whole reason this exists is the second ability, and the mana rock strapped to it is scaffolding: a way to justify a two-mana permanent that would otherwise sit dead until you found a reason to turn something into an artifact. That reason is usually artifact removal. Once a nonland permanent gains the artifact type, every Shatter, every Abrade, every artifact-specific answer suddenly reads it as a legal target, and a small class of effects that only trigger on artifacts leaving play comes online. The tempo cost is spread across two taps: it converts only one target per turn, and only the permanent it points at, so the enabler asks you to already have the payoff assembled rather than digging toward it. Liquimetal Coating did this on a permanent that produced nothing, and the torque's tweak is to fold in a colorless mana source so the card is not a total blank on the turns you have no target worth changing. That widens the ceiling of the second ability, too: turning your own permanents into artifacts opens sacrifice and recursion lines that have nothing to do with removal, and pointing it at an opponent's creature or planeswalker hands your artifact hate a target it could not otherwise touch. It is a converter, and its value is exactly the value of whatever you have waiting for the thing it converts.