Thunderstaff

Two effects pull in opposite directions and the connective tissue between them is the tap state. Leave it untapped and every attacker hits you for one less, a flat damage-prevention shield that scales with how many creatures swing at you. Tap it for the pump and that shield drops, so the card asks you to choose each combat: defend or push damage, never both at once. That is a genuinely odd lever for an artifact to offer, since the cost of attacking better is becoming temporarily worse at blocking the counterswing. The prevention is modest (one point per creature is real against a wide board and irrelevant against a single fattie), and the activated ability is a global anthem rather than a single-target trick, which positions the whole thing as a wide-aggro support piece in an era that mostly cared about big artifact threats. It reads as a deliberate attempt to give a go-wide deck both a defensive floor and an alpha-strike button in one slot, then prices the two against each other so neither comes free. Whether the card does anything swings entirely on how many bodies are in play on both sides, a narrower band than the flexible-looking text suggests.