Exhaustion

A Time Walk with the polarity reversed: instead of granting an extra turn, it strips the resources out of the opponent's next one. Their lands stay tapped, their blockers stay sideways, their creatures and lands arrive at their next untap step frozen. The clever part is what the card declines to do: no creatures die, no cards change hands, no permanent leaves play, yet it manufactures a one-turn window where the opponent is functionally a turn behind on both mana and defense. That makes it a combo and tempo enabler first and a control card never. The effect is only worth a card when you have something planned for the gap it opens: an alpha strike that gets through unblocked, or a mana lead you can spend uncontested. The Portal line favored clean, beginner-legible templating, and this is a surprisingly advanced idea wearing that plain coat. Denying an untap step is an asymmetric tempo swing that only pays off for a player who already understands what a turn is worth. The sorcery timing is what enforces the planning. Because you cannot deploy it at instant speed to stun an attacker mid-combat, the burden sits entirely on you to build the turn around it in advance, paying for the swing in foresight rather than mana.