Aven Heartstabber

The graveyard condition is the piece worth studying here. Most graveyard payoffs count raw card totals or a single card type; this one asks for a spread of costs, which quietly rewards a deck built out of a curve rather than a pile of the same one-drop. That pulls in a direction most self-mill decks do not naturally go: it wants variety in the yard, not just volume, so a graveyard stocked with cheap cantrips and mid-cost spells fuels it better than a stack of identical fodder. Meeting the threshold flips a fragile 1/1 flier into a 3/3 flier with deathtouch, a body that trades up in the air and taxes any blocker into a losing exchange. The death trigger closes the loop by feeding the same engine that turns it on: two cards to the yard, one back to hand, so the creature actively builds toward its own condition even as it dies. That is the tension the design resolves, a self-mill enabler that also profits from self-milling, tying the enabler and the payoff into one two-mana body. Because the buff comes from a static ability, it applies continuously rather than locking in once: exile the graveyard and it switches off, refill it and it returns, which makes tracking your own count a live part of piloting it.