Rustrazor Butcher

First strike and wither on the same body make for a small, mean piece of combat math. First strike grants its own damage step ahead of normal combat damage, so the wither hits first, applying its -1/-1 counters before a surviving blocker ever swings back. The trick is that those counters are permanent: a creature that lives still walks away shrunk, which turns combat from a question of who dies into a question of who erodes. The 1/2 frame is the leash on all of it. Trade math only breaks lopsided in narrow cases: a blocker with one toughness dies in the first-strike step, and a blocker with power two or less drops to power one and fails to kill the goblin back. Anything bigger (a 3/2 falls to a 2/1 and still connects for lethal) trades up against you. This is a file, not a brawler. It wants to poke repeatedly at a defender's toughness, treating each block as a chance to leave a permanent dent rather than to deal lethal once. Hand it any source of extra counters or counter doubling and the per-hit shrink becomes a slow removal engine, but it asks for nothing fancy to do its work: it simply makes blocking it a losing proposition, each hit chipping a little more off whatever stands in front of it.