Fire Navy Trebuchet

A wall that never leaves the ground yet contributes to the red zone every single turn you commit to combat. The 0/4 body with reach is a competent defensive floor, blocking fliers and grounders alike, but the ability inverts what a Defender is normally for. Instead of asking you to sit back and stall, it keys off your own attack step: declare attackers anywhere on the board and it spawns a 2/1 flier already tapped and already swinging. That token dies at the next end step, so there is no accumulating air force to protect, no permanent presence to trade away, just a single evasive point of pressure that must be spent the turn it appears. The trigger fires once per combat when you declare one or more attackers, not per attacker, so the reward is for attacking at all rather than for overcommitting: even a lone ground creature going in unlocks the flier, and a board full of attackers unlocks exactly the same one. The sacrifice clause is what keeps the whole thing from being a repeatable token engine; the value is a clock you rent one turn at a time, not a board you build. The result is a defensive piece that quietly demands you keep attacking to extract its upside, a stall-behind-the-wall body that only pays out when you are also pushing damage.