Dimir Cluestone

Three mana for a mana rock is a full mana behind the Signet baseline, and the rock answers for that tax with a clause the Signets never had: a built-in escape hatch. Tap it early to fix a guild's colors and accelerate while the game still needs the help. Then, once acceleration stops mattering and a plain rock would rot in hand, spend the colors it makes, tap it, and sacrifice it to draw a card. That is the whole design idea: the rock fixes and ramps in the early turns, then cashes out late, so the slot never goes fully dead. The cantrip is deliberately expensive, gated behind both colors plus the tap so it cannot be looped or rushed; it is a one-shot cleanup, not an engine. What the slower rate buys is a fixing piece that does not punish you for drawing it in topdeck mode, the recurring weakness of every rock that does nothing but make mana. This is the conservative, durable answer to a tension the Signet generation left open: trade a turn of speed for the guarantee that the card is never a blank.