Great Desert Prospector

A wide board turned into a mana battery, all at once. Powerstone tokens ramp toward artifacts specifically (their mana refuses to pay for nonartifact spells), so this creature only pulls its full weight in a shell that wants that colorless mana pointed somewhere: big artifacts, expensive equipment, activated abilities. The count scales with what you already have on the battlefield, which inverts the usual ramp math. Most ramp cards want an empty board and an early turn; this one wants a full board and rewards the go-wide plan you were already on, converting each of your other creatures into a tapped stone. That the stones enter tapped holds the payoff to the following turn, so it accelerates rather than combos, and the 3/2 body is priced as an afterthought to the trigger. The fenced-in mana is what balances the burst: it hands you an armful of ramp too restricted to abuse in a generic pile, but exactly right when the deck is already committed to casting and animating artifacts. Untethered from that restriction, the trigger would be a strictly-better mana rock explosion; chained to it, the card asks you to have already built the artifact-hungry board it feeds.