Sidisi, Brood Tyrant
The genius here is the loop between the two abilities. Self-mill is normally a cost: you trade cards in hand for cards in the bin and trust your deck to convert them later. This design collapses the cost into the payoff by making the mill itself the engine. A creature card hitting the graveyard from your library spawns a 2/2 Zombie, so the deck wants a creature-dense library, and the bodies it produces are the resource you were "losing" reframed as the resource you were building. Note the exact trigger shape, though: it fires once per event, not once per creature. Mill three creatures at a stroke and you make a single Zombie, so the reward tracks how often you dig, not how many bodies land per dig. The enters-and-attacks trigger guarantees the mill fires twice on a clean curve (once on the way down, again on the first swing), and because every attack re-triggers it, the engine keeps running each combat rather than asking for a separate sacrifice outlet or activation. Sidisi codified what self-mill could be when the graveyard is treated as a deliberate resource rather than a side effect: not a recursion shell that retrieves what it loses, but a value engine that converts library depth directly into board presence. The Snake Shaman framing carries the Sultai philosophy of plundering the dead for power, and the card backs it mechanically.
