Silversmote Ghoul

A recursive engine wearing an aggressive body, built to make lifegain a resource rather than an aside. The end-step check rewards a specific kind of deck: one that reliably crosses three life gained per turn, at which point the Ghoul climbs back from the graveyard tapped and waits to do it again. That loop is the whole design, and the sacrifice ability is what turns the loop into an economy. Each time it returns, you can cash it in for a card, then bring it back next turn once the lifegain triggers, converting an incidental lifegain payoff into a steady stream of cards and sacrifice fodder. The three-life threshold is the throttle: no gain, no return, so the Ghoul stays inert in the yard unless the deck is actually built to feed it (lifelink attackers, blood artist effects, incidental drain) rather than slotting into anything black. Both halves feed the same machines: the sacrifice fits any aristocrats shell that wants bodies dying, and the return fits any shell that wants lifegain to matter. It descends from black's self-recursion threats, the ones that ask you to pay a specific upkeep in exchange for a body that never really leaves, closer in spirit to the graveyard-loop enablers than to a straightforward beater. The 3/1 frame is almost incidental; the value is in never having to draw it twice.