Mine Bearer

The trade here is a body for an activated ability, and the timing is the whole story. Tapping and sacrificing to destroy an attacker is a defensive instant-speed answer disguised as a creature: it sits on the board as a 1/1 chump until combat is declared, then converts into unconditional removal of a single attacker. That window is the constraint. The card cannot touch a blocker, cannot remove a threat outside combat, and cannot stop a creature that simply sits back; it punishes only the player who commits to the attack. The tap cost adds a second restriction, since the creature has to have been on the board a turn to act, so it telegraphs its presence before it ever fires. There is a third seam: because the ability targets and the body is a white source, it whiffs against an attacker with protection from white. The design belongs to a long white tradition of bodies that double as conditional removal, where the toughness is almost beside the point and the value lives in the sacrifice clause. What you are paying for is not the 1/1 but the promise that an attacking creature, regardless of size, dies the moment it swings. That promise is narrow by construction: it answers aggression and nothing else, which is one of the ways white earns its kill spells, by bolting them to a fragile body and a combat-only window.