Mercenary Informer

The Mercenary tribe of that era recruited downward: a larger Mercenary fetched a smaller one onto the battlefield, building a toolbox chain that assembled itself a creature at a time. This card runs that machine in reverse, paying three mana to sink any nontoken Mercenary, including an opponent's, to the bottom of its owner's library. Against the recruitment engine that bottoming is a soft answer that buries a key piece deep with no fast recovery short of a tutor or a fresh shuffle; in the mirror it doubles as a survival trick, pulling your own creature out of a sweeper's range and tucking it back into the deck to be recruited again later. The protection clause is the second tell. Black was the color built to police the Mercenary chain, so making this creature untargetable by black spells and abilities from black sources is a pointed hedge: it sidesteps black removal in exactly the lane where the subtheme expected black to keep order. The result is a regulator rather than a beater, a 2/1 whose job is to manage the rate at which a specific engine comes together. Stripped of that synergy web the body is unremarkable, but the bottoming ability is one of the more precisely aimed answers a tribal block of its era produced: a removal-adjacent tool that only the deck it exists to discipline can fully wield.