Vizier of Remedies
A counter-reduction effect whose printed framing badly undersells it: read it as defensive, a way to shrug off a single counter from an opposing wither or infect source, and you miss the load-bearing words. When exactly one -1/-1 counter would land on something under your control, "that many minus one" resolves to zero, so nothing arrives. The original context was voluntary self-counters for undercosted stats: a body that takes its counters through this static ability keeps its full size, converting a drawback into pure rate. But the replacement effect does not ask why the counter is coming, and persist supplies a perfect victim. Persist returns a creature with exactly one -1/-1 counter; erase that counter before it lands and the creature comes back clean, free to die and return with no ceiling. Add a sacrifice outlet or a recurring damage trigger and the loop runs as long as you feed it. The 2/1 is incidental, a delivery vehicle for a static line whose real job is to break an existing keyword rather than to win combat: marginal protection on its face, an engine in the right shell.
