Ornate Kanzashi

Theft from the top of an opponent's library is the gimmick, and the design exposes exactly how much friction that gimmick needs to stay fair. Each activation steals only the single top card, only from a chosen opponent, and only for use that turn: you exile it and lose it if you cannot cast or play it before cleanup. That timing window is the entire constraint. The card you pull might be a land you have no use for, a spell you cannot afford on the mana left after the activation, or a creature you would rather not commit. So the artifact rewards a deck flush with open mana and flexible enough to actually deploy whatever surfaces, not one that wants a specific card. It is a value engine with no guaranteed value, an information-and-resource trade where the resource is whatever the opponent's library happens to offer. The lineage here runs through every card that mills or peeks at the top of a deck and then lets the controller play the spoils; this one is unusual in that it points the effect entirely at an opponent rather than digging through your own library. The repeatable activation is what gives it ceiling: untap, pay again, take another card. In practice the cost of doing that turn after turn, plus the cleanup-step clock on anything you grab, keeps the engine honest without any printed counter or sacrifice clause doing the policing.