Summon Undead

The self-mill here is not a downside grafted onto a reanimation spell: it is the fuel line. Most cheap reanimation demands a graveyard already stocked through discard, fetchlands, or an earlier turn's dredging. This design collapses setup and payoff into a single card, binning three off the top and then pulling a creature back, so the very act of casting it can dig up its own target. That self-sufficiency comes with a random dig and a middling five mana: you are trusting the top three cards to either bin a fat threat you can then return, or to have already put one there for you. The price buys unconditional reanimation with no restriction on the returned creature's power, converting library mass into a body without demanding a discard outlet or a pre-loaded yard. It belongs to the reliable, grind-it-out branch of black reanimation rather than the turn-one Reanimator explosions, but the ordering baked into the text is what distinguishes it: the mill resolves first, so the fill and the return happen in one cast rather than across two cards or two turns. The whole exchange lives or dies on whatever those three cards happen to be, which makes it a self-contained engine for decks that would rather find their reanimation target than have to draw it first.