Horned Stoneseeker

The Powerstone here comes tethered, and that tether is the whole design conversation. A menacing 2/2 for two that hands you a ramp artifact on entry is an aggressive rate for red, but the leaves-the-battlefield trigger claws one Powerstone back the moment the Lizard dies, which is a deliberate hedge against the obvious abuse: flicker it, sacrifice it to something, and the token disappears with the body rather than compounding. Powerstones themselves are the balancing mechanism, since the colorless mana they produce cannot cast nonartifact spells; the ramp is walled off toward artifacts, equipment, and activated abilities rather than fueling a red aggro curve. That constraint is what keeps this from being a simple two-mana accelerant into three- and four-drops. The creature invites a build that spends the mana on things it is actually allowed to spend it on, which points at artifact-heavy shells rather than the burn-and-beatdown red usually wants. It is a rare case where the ramp piece and the artifact payoff want to live in the same deck, with the fragility of the Powerstone (one bad block, one removal spell, and the token goes with it) standing in for the usual downside a two-power evasive body would otherwise skip paying.