Malevolent Witchkite

A 5/4 flyer for six is the floor; the enters trigger is the story, and it asks for a choice rather than demanding one. Nothing forces you to sacrifice: the ceiling is a hand full of cards paid for entirely in permanents you were finished with, and the sacrificial fuel is exactly what a black deck tends to have lying around by turn six (spent Treasures, expired enchantments, a board of tokens whose combat value has already been extracted). The design converts board width into card advantage. The gating is deliberate: draw-on-a-stick lives on a knife's edge between too cheap to be fair and too expensive to be exciting, and the answer here is to price the payoff in resources you had to build up first rather than in mana. Stapling the conversion to a body worth casting on its own resolves the other half of the problem. You are not spending a card slot on a Skullclamp-style engine that does nothing until it has something to eat; you are spending it on an evasive threat that happens to refill your hand when it lands. A deck with no disposable permanents still gets a 5/4 flyer pressuring life totals on its own timeline; a deck built to churn out tokens and Treasures gets a haymaker that cashes the whole board into gas the moment the dragon resolves.