Powerstone Shard

The whole design lives in the four words "named Powerstone Shard." Each copy taps for one colorless per Powerstone Shard you control, so the first one is a strictly worse Manalith while the third or fourth turns each Shard into a real accelerant. This is the count-your-own-name toy (the mechanic that makes cards like Relentless Rats better in multiples) ported onto a tap-for-mana artifact, where the standard four-copy limit becomes the ceiling on how steep the curve can get. Drawing your second copy doubles the output of the first, and every copy after that compounds; the deck that runs a lone Shard is holding a three-mana rock that adds a single colorless, while the deck that commits to the full playset builds an engine that scales with its own redundancy. That escalating floor is the discipline: the card punishes the half-measure and pays off the all-in. It counts only the Shards under your own control, not every copy in the game, so opponents cannot feed your engine and mirror matches stay contained. And it produces colorless exclusively, which keeps it out of the greedy-manabase conversation and squarely in the ramp-and-artifact lane. The clever part is not the effect but the target of the count: pointing a mana artifact at itself turns a curiosity into a payoff that rewards drawing more of the same card, the rare rock whose value lives entirely in the copies beside it.