Thran Spider

The symmetry here is the tell. Handing your opponent a Powerstone token when you enter looks like a mistake until you remember what Powerstones can and cannot do: they make colorless mana that pays for artifacts and activated abilities but not for casting most spells. So the giveaway is a hedged one. You get a ramp rock that this spider is already positioned to use (its own artifact-dig ability, the wider artifact plan around it), while the opponent gets a token that is dead weight in a creature deck and only live in the same kind of construction you are running. The reach body is the other half of the design: a 2/4 wall that blocks fliers and holds the ground while the Powerstone accrues toward the seven-mana activation, a self-contained value engine that stalls the board and refills the hand at the same time. The card is a compact statement of what Powerstones were built to be: mana that is worth something only if you have already committed to the artifact axis, so the seemingly generous split is really an asymmetry disguised as a fair trade. Every line on it points the same direction, toward a grindy artifact midrange where a wall that draws you gas is exactly the tempo you want.