Meteor Sword

Seven mana buys two effects that Equipment normally keeps far apart: a hard removal spell that hits any permanent, and a permanent +3/+3 anchor that survives the creature it was strapped to. The design logic sits in that "when this Equipment enters" clause. Most Equipment does nothing the turn it drops; the destroy trigger fires the moment the artifact resolves, whether or not there is a creature on the board to hold it, so the seven mana is never a dead investment. The removal is the payment you make up front; the +3/+3 and the reusable equip cost are the residual value that keeps working long after. Compare it to the older split between removal-on-a-stick creatures and equip-only buffs: this collapses both into one card that answers a threat, then hangs around to make the next attacker bigger, and can shuffle across your board at three mana a hop. The catch is the equip clause is sorcery-speed, so the buff cannot ambush combat the way an instant would; the destroy trigger only comes once, on entry, and reattaching later gives you the stat boost but never a second kill. It rewards a board that already has bodies to move it onto, and punishes the empty-handed cast that spends seven mana to blow up one thing and set a naked artifact on the table.