Reprieve

White does not counter spells, so it answers the stack the only way its slice of the color pie permits: it sends the spell home. Return the target to its owner's hand and draw, and you have built an Unsummon aimed one zone higher, closer in spirit to the buy-a-turn half of Remand than to any true counter. The distinction is the whole point. The opponent keeps the card, but the mana they invested is spent, so they have to find it again next turn to try a second time. Nothing is denied, only delayed, and delay is priced accordingly. Against a threat that has to connect to matter, one turn is often the gap between racing and dying; against a combo assembling its payoff, one turn is a stay of execution, and the cantrip means you paid nothing in cards to buy it. But the symmetry cuts both ways, which is exactly what keeps a two-mana answer to anything from being oppressive: a patient opponent simply recasts next turn, sometimes with protection up. The seam worth noting is that the target need not be theirs. Point it at your own spell to save it from a counter on the stack, bouncing it out of the fight to replay clean later. Instant-speed interaction that touches the stack, replaces itself, and costs two is a pointed expansion of what white is licensed to do: not a hard no, but a firm "not yet," sold at the price of a cantrip.