Thrull Retainer

An Aura that pays for itself twice over: the +1/+1 is a small downpayment, but the real value is bundled into the sacrifice clause, which lets a creature shrug off a removal spell or a bad combat block exactly once. That packaging is the design point. Most regeneration of this era lived as an activated ability tied to a permanent that stayed on the board; here the regeneration is still an activated ability (note the colon), but one that consumes the Aura itself as its cost, so the card spends down to nothing the moment it does its job. The stat bonus exists to make the enchantment worth running before the rainy day arrives: the creature is bigger now and protected later, with the protection cashing out as a clean tempo swing the first time an opponent commits to killing the thing. It is a tidy expression of how the period thought about black: small, attritional advantages stacked one mana at a time, where the threat of an answer is sometimes worth more than the answer itself. Because the Aura is a face-up permanent, the opponent can see the regeneration shield plainly, which is the point; they have to respect it, route their removal around it, or spend a second spell to break through. The catch is the Aura's structural fragility: bounce the enchantment and the creature loses both halves, the classic card-disadvantage risk that has always priced down creature Auras relative to their printed rate.