Sanitarium Skeleton

The recursion is the entire pitch: a one-mana body that buys itself back from the graveyard, over and over, provided you keep paying the toll. It descends from the self-returning fodder that Reassembling Skeleton codified, and the genealogy matters because these creatures are not built to attack or block well. They are built to die on cue. A 1/2 chump that comes back is exactly what sacrifice engines want: a renewable input for outlets that demand a creature, a recurring trigger for death-payoffs, a body you can throw under an attacker and reclaim later. The activation lives in the graveyard, so it parks there as a standing resource you fire off on any open mana until you need another swing of the loop. The price of that loop is what stops it from being oppressive. Because it comes back to your hand instead of straight to the battlefield, a full cycle costs four mana per pass ( to retrieve it, then to recast it before you can feed it to an outlet again). That is a real tax, slow enough that the card never threatens to become a value engine by itself, only a steady drip you fold into a deck already built to monetize repeated deaths. On an empty board it does nothing; wired into a machine that eats creatures, it never runs out.