Hourglass of the Lost

The counter it builds toward is the counter it spends. Every tap for white quietly loads the payoff: a time counter accrues each time you use it as a mana rock, so the artifact's ceiling depends entirely on how patient you were with it. When you cash out, you remove X counters, exile the whole thing, and reanimate every nonland permanent in your graveyard at exactly mana value X. That single-value clamp is where the design lives. This is not a Living Death dumping the yard back wholesale; it demands a graveyard stocked with permanents that happen to share one number, which turns deck construction into a curve-stacking exercise instead of a heap of unrelated bombs. Wait long enough and you return a fistful of three-drops at once, or fewer, larger threats if you stalled to a higher count. The sorcery-speed restriction and the self-exile keep it honest: it is a one-shot engine, not a recurring loop, and the mana it produces along the way is the tax you pay for the eventual haymaker. It rewards a build that treats the ramp phase and the reanimation phase as the same clock, filling the graveyard with a chosen mana value while the counters tick up. The whole thing hinges on that convergence: ramp now, reanimate later, on a single stat you get to define.