Nemesis of Reason

Ten cards per swing is a number chosen to do one specific thing: turn a mill clock into a kill clock that outpaces decking out by attrition. Many mill creatures chip away in twos and threes, asking you to assemble a critical mass before the plan matters. This one inverts the math. The trigger fires on the declaration of attackers, not on combat damage, which is the load-bearing detail: the ten cards are gone before blockers are even chosen, so a chump block stops nothing. Two attacks empty twenty; a third makes thirty. The 3/7 body is the more interesting half of the equation. A high toughness on a mill threat lets it survive the ground stalls and gang-blocks that mill plans naturally invite, since a deck built to deplete a library tends to fold into a defensive crouch while the count ticks down. Seven toughness lets the creature keep swinging through the very board states it creates, and because the mill happens at attack rather than on connection, it does not even need to push damage through to do its work. The real cost is that the ability only fires when this attacks, so it has to stay alive and stay aggressive against a removal-heavy answer suite to fire more than once. A mill payoff that wants to be the aggressor rather than the engine is rarer than the rate suggests, and the friction between a defensive toughness profile and an attack-only trigger is what defines how it plays.