Tower of Coireall

A two-mana artifact that exists to answer exactly one creature type, and one that barely populated the game it shipped into. Walls were a purely defensive presence with no way to attack, so the design problem here is razor-narrow: pay two, then tap to make a single attacker ignore them for a turn. That is the whole transaction. The cost structure tells the story of how mechanically literal early design could be; rather than a keyword like trample to climb over a Wall, or removal to clear it, the answer is a dedicated artifact whose only verb is "this creature can't be blocked by Walls." It accomplishes nothing against any other creature, accomplishes nothing while you defend, and sits dead the turn a Wall is not on the table. The repeatable tap is the only thing keeping it from being a one-shot effect, and even that repeatability is fenced behind one creature per activation. It reads now as an artifact of a period when designers built specific keys for specific locks, before evasion was abstracted into trample, flying, and menace doing the heavy lifting across every set. It is the road not taken: the moment before Magic decided that a problem as small as "Walls block my creatures" should be solved by the creature itself, not by a colorless permanent built to address one tribe.