Spincrusher

The trick here is that the two abilities point in opposite directions, and the counter is the currency that lets you choose which one to spend. Block, and the body grows: a recurring defender that gets sturdier every time it eats a hit, slowly building a reserve of counters. Then, when the board state flips and you want to push damage, you cash those counters back out, one at a time, to make it unblockable. It is a defensive engine that converts stored toughness into evasion on demand, a wall that decides to start attacking once it has fed. The 0/2 body means it deals nothing on offense until it has banked enough blocks to be worth removing counters from, so the design enforces a sequence: defend first, threaten later. As an artifact creature it sits in any color, which is the natural home for a construct whose entire value is patience. The card belongs to the broad Darksteel project of putting +1/+1 counters at the center of artifact design rather than treating them as a green keyword, and Spincrusher is one of the purer expressions of that idea: a creature that stores combat experience as physical counters and then trades that experience for an opening. The economy is tight (each unblockable turn costs a counter, so the reserve never runs deep), which keeps it from ever becoming a fast clock. It is a slow accumulator pretending to be a blocker.