Elbrus, the Binding Blade // Withengar Unbound

The combat damage is the trigger, but the patience is the point. As an Equipment it does almost nothing: a one-mana equip cost and a +1/+0 bonus on a creature that has to land a hit on a player before anything happens. That hit is the whole transaction. The instant equipped damage connects, the blade unattaches and flips into Withengar Unbound, a 13/13 with flying, trample, and intimidate that arrives the moment your evasive attacker resolves its damage step. The thirteens are not incidental; the demon trades in them. A 13/13 body, and then thirteen more +1/+1 counters every time any player loses the game, a clause that turns a multiplayer board into a runaway threat the instant the first opponent dies. That last ability is where the card outgrows the era's parade of flip-on-connect Equipment: most of those resolve into a respectable body and stop there. Withengar is built to escalate past the table, rewarding the death it helped cause with the means to cause the next one faster. The design tension is honest about the cost: you must first solve the puzzle of connecting a low-impact equipment-bearer with the opponent, and only then do you collect a finisher that scales with carnage rather than mana. It is a payoff card disguised as a piece of equipment, and the disguise is the entire setup.