Thraxodemon

The pricing tells you exactly what this Demon is not for. Three generic mana plus the tap and a sacrifice, all to net a single card, is a deliberately steep rate: nobody wants to run this every turn, and that cost is precisely what stops it from spiraling into a free repeatable value loop. The trade is a body attached to a reliable outlet, which pays off most when the permanents you feed it are worth more dead than alive. Tokens, spent utility artifacts, creatures with a death payoff: the ability converts otherwise stranded pieces into raw cards, and does it at a color and mana value cheap enough to slot in without demanding a deck built around it. Because the activation carries no sorcery-speed clause, it fires at instant speed, so you can sacrifice a creature in response to targeted removal and squeeze a card out of a permanent that was already dying. A 2/2 for two that pivots into a slow draw engine once the board stalls belongs to a long line of unglamorous outlet-plus-payoff bodies black has printed in many shapes over the years. This one asks for patience and full mana rather than raw efficiency, a fair exchange for a creature that doubles as a warm body and an answer to your own dying permanents.