Natural Affinity

Animating every land on the battlefield is a symmetrical effect that reads like a joke until you notice which way it breaks. The card touches all lands, yours and the opponent's, but only one player decides when to cast it. Aim it at an opponent's turn and their entire mana base becomes a field of 2/2 creatures, suddenly exposed to a board wipe or anything that punishes a battlefield full of bodies. It is a sweeper that converts an opponent's mana into casualties, and the instant-speed timing is doing the heavy lifting: the window opens after they have tapped out or at a moment of your choosing, and closes the moment the spell resolves into a kill condition you supply separately. The land-animation lineage runs through sustained enchantment effects like Living Lands and Nature's Revolt, but those committed you to an ongoing plan and left a permanent the opponent could remove. This is a one-shot instant instead, which recasts the effect as a combo enabler rather than a deck identity: it asks for a partner (mass removal, a damage spell, a saboteur) and pays off in a single turn rather than building an engine. The "until end of turn" clause is what buys the cheaper rate; the bodies evaporate at cleanup, so the trick has to cash out inside the same turn or it cashes out nothing. There is no follow-up window, only the one you set up before casting.