Banshee's Blade

Equipment that grows by being used, not by being paid for. Attach it and the creature gains nothing at first, because there are no charge counters yet to feed off. But every time the carrier deals combat damage, blocked or not, it banks a counter that never goes away, so a creature that keeps connecting turns this into a snowballing threat. The permanence is the whole engine. The counters live on the Equipment, not the body, so the accumulated bonus survives the carrier's death and rides along when you re-equip onto a fresh attacker. That makes the buff sticky in a way aura-style pumps never are: kill the creature and you have erased nothing the Equipment has earned. The cost of that design is the slow start. The first turn buys you a body with no statline change, the payoff depends on landing damage repeatedly, and the engine only compounds if you can keep an attacker alive long enough to feed it. As one of the early Equipment designs from the era that introduced the subtype, it sits beside the flat-rate staples of its peers as the patient, self-fueling alternative: where most Equipment hands you a fixed bonus the moment it attaches, this one makes you grind for the bonus, then stops asking for mana entirely once the counters are stacked.