Trumpet Blast

The pump effect that taxes the attacker more than it ought to: the bonus only sticks to creatures already committed to combat, so the spell pays off exactly when the board is already swung wide and the math is simplest. That conditional is the whole design. An unconditional team buff at this cost would warp every race; restricting the +2/+0 to attackers means the value scales with how many bodies you've thrown forward, and the card does nothing on defense, nothing pre-combat, nothing as a trick to win a one-on-one block. It is a finisher dressed as a combat instant, the kind of effect a wide red or token board cashes out for lethal after the defender has already declared blocks and assigned what they thought was a safe trade. Red has printed many descendants of this template, most of them cheaper or wider, but the core lesson holds: a mass pump is only as dangerous as the board it's pumping, and the attack-only clause is the lever that keeps an otherwise blowout-grade effect honest. Outside of a developed offensive board it is a dead card, and that is by design rather than oversight.