Mindless Null

A drawback templated as a tribal handcuff. A 2/2 for that cannot block is already a below-rate body; the can't-block clause turns it into a creature that exists only to attack, useless on defense unless a Vampire is on the battlefield to lift the restriction. The condition is not a payoff and does not pretend to be one: meeting it just removes the penalty, leaving you with a plain 2/2 that can now plant its feet. That is the whole mechanic, a soft color-of-deck fence that never improves the card, only stops punishing you for running it outside its intended shell. Pull the body away from Vampires and the leg-iron stays on; surround it with them and you have an unremarkable beater that no longer trips over its own ability. The Zombie type carrying the Vampire requirement is small flavor doing the rules text's job: a thrall with no will of its own, holding its line only when a master is present to command it. There is no upside text here to recover, and no reading of the stat line that makes three mana for a 2/2 a bargain. The interest, such as it is, lives entirely in the gating: a restriction that costs nothing to satisfy in the deck it was sorted into and never quite goes away anywhere else.