Thousand-Year Elixir

Two effects bolted together for the same buyer: the player who wants a creature's tap ability and wants it now. Granting pseudo-haste to activated abilities is the headline, since it lets a freshly-cast creature tap for value the turn it lands instead of waiting out summoning sickness. But the second line is what gives the artifact its longevity: untapping a target creature for one mana means a single tapper, mana producer, or activated-ability engine can fire twice a turn, or fire on an opponent's turn at instant speed. The two abilities feed each other. Haste-on-activation gets the engine online a turn early; the untap doubles its output once it is. That double-up is the design's real reach: any creature whose tap ability is worth doing once is worth doing twice here, which quietly turns ordinary value creatures into the kind of repeatable engine that warrants building around. It is a piece for a deckbuilder who thinks in activations per turn rather than power on board, and it has stayed relevant across eras precisely because the pool of creatures with abilities worth untapping for only ever grows. The first effect is the convenience; the second is the combo enabler that keeps it in the conversation.