Shamble Back
A one-mana token-maker is a modest thing; the exile clause stapled to it is what earns the slot. Denying an opponent's recursion target while still building your own side of the board is a rare two-for-one at this rate, and it costs no tempo doing it. In a color that treats the yard as a second hand, stripping a would-be Gravecrawler or Reveillark loop before it can start matters as much as the 2/2 you get in return. The two life is the smallest part of the package, a rounding error that nudges close races. There is a real cost to the price, though: the card needs a creature card sitting in some graveyard to do anything, so early or against a clean board it stalls in hand, an answer waiting for something to have died. That dependency is exactly why the effect fits under a single black mana; it is reactive by construction, only ever as good as what has already hit the yard. Black has long stitched utility onto its cheap token-makers, but most pay for it in life loss or card disadvantage. This one pays in exile, the currency that carries the most weight when both players are mining their graveyards for cards a second time.
