Metallic Mastery

Threaten effects yank a creature off an opponent's board for one swing; this one points the same temporary-control template at artifacts instead, and that change of target reshapes what the spell is for. Most artifacts have no power or toughness to attack with, so the untap-and-haste rider matters less for combat than for activated abilities: the play is to hijack a powerful tap ability before its owner can use it, or to commandeer an artifact creature and send it at the player who built it. Because this is sorcery-speed, none of that can happen on someone else's turn: there is no instant-speed redirect, no interrupting an opposing attack. Everything must be set up and resolved on your own main phase. Borrowing a mana rock looks tempting until the math intervenes. At three mana to rent a Sol Ring you spend more than the two it returns, and even larger rocks like Gilded Lotus or Thran Dynamo only break even, so this is never the ramp-explosion line it first appears to be. The real payoff comes from refusing to give the artifact back: pair the steal with a sacrifice outlet and the one-turn loan becomes permanent removal, the same trick that lets Threaten plus a sac outlet eat a creature for good. It does nothing against an artifact-light board and a great deal against an artifact-heavy one, a build-around answer that bets the whole turn on someone else holding the right toy.