Celestial Sword

The buff and its own undoing are sold together: +3/+3 lands on a creature you control, and that same creature is scheduled to die at the next end step. The reason is structural, and it predates the equipment template entirely. A repeatable, no-strings combat pump on an artifact would have warped a set this old, so the pumped body becomes the price of pumping it. That makes this a one-turn finisher, never a value engine: point it at a creature when the extra power closes a game or trades up in combat, accept the loss, and pay three mana plus a tap for each swing. The arithmetic is punishing (six to deploy, three to fire, a permanent spent for every burst). The death itself runs on a delayed triggered ability: when the activated ability resolves, the buff applies and a delayed trigger gets queued to fire as the end step opens. That detail is also the card's one escape hatch. Because the sacrifice is a normal trigger that uses the stack, it can be answered (Stifle counters it outright) or sidestepped before it ever fires (bounce, blink, or phase out the creature, and the trigger finds nothing to sacrifice). The default line is to eat the loss, but the loss is not mandatory. It belongs to the generation of clunky, expensive Ice Age artifacts the game would later solve far more cleanly: an early sketch of combat-trick-by-artifact, weighed down by a cost severe enough that the buff only pays off in the rare turn where one extra attacker ends things.