Fountain of Renewal

One life per upkeep is the slowest lifegain drip a permanent can offer, and that feebleness is the whole design. The artifact does nothing to defend you, generate tempo, or pressure the opponent; it exists cheaply and triggers reliably, which is precisely the resource it produces. Any payoff that asks "did you gain life this turn?" gets an automatic yes every upkeep, without you spending a card or a click to secure it. The single life is almost incidental: what matters is the recurring event, fired for one mana and no upkeep tax on your other lines of play. The sacrifice clause is the graceful exit: once your payoffs have resolved or the counting stops mattering, the artifact cashes itself in for a card rather than rotting on the battlefield, so an early commitment never becomes a late-game liability. In a vacuum it ranks among the weakest permanents you can name, and the restraint is deliberate: a free per-turn lifegain trigger stapled to a body, or paired with a faster clock, would be trivial to abuse. The card lives or dies on whether the rest of the deck converts small repeatable lifegain into something larger. On its own it is inert; as a metronome for a lifegain-matters shell, it keeps perfect time.