Hivis of the Scale
A theft card built around a resource almost nobody at the table had in 1996: Dragons. The mechanism is a tap-lock with a self-imposed catch. The control effect persists only while Hivis stays tapped, and the may-not-untap clause exists precisely so you can keep that condition true: each untap step you choose to leave Hivis tapped, holding the leash. That turns the 3/4 body into a permanent commitment rather than a repeatable trick. The frozen creature is Hivis itself, not the Dragon you took: the engine driving the theft sits there tapped and contributing nothing to combat as long as you want to keep the stolen Dragon. The friction is the balancing valve. There is no version where you tap, steal, and untap to do it again next turn for free, and no version where the stolen Dragon comes with your own body still active. It is a one-Dragon-at-a-time clamp that costs you a creature to maintain. What dates the card is its narrowness; it does nothing against a board with no Dragons, and it asks the rest of your deck to either supply targets or punish the single creature your opponent built around. The design illustrates conditional control cleanly, with the duration written directly into the card and the upkeep cost folded into the tap state rather than charged in mana.
