Frostveil Ambush

Five mana to tap two creatures and hold them down for a turn is a rate that reads worse than it plays, and the cycling clause is why the card earns a slot anyway. A dedicated tapper at instant speed does one thing: it buys a combat step, either freezing two would-be blockers before an alpha strike or neutralizing two attackers who now sit tapped through their next untap step. That is a narrow window, and against the wrong board it does nothing at all. The floor is the answer to the ceiling being conditional. When the effect is dead in hand, turns it into a fresh card, so the slot never becomes a mulligan-inducing brick. This is the design logic behind cycling as a keyword: it lets a card be built with a sharper, situational effect than a maindeckable card would normally carry, because the discard-to-draw escape hatch absorbs the downside. The mode you want (a tempo swing that opens two lanes or shuts two down) is priced high precisely because it is paired with an out that costs almost nothing. The card is really two spells stapled together at different points on the power curve, and the deck decides at each draw which one it holds.